Sunday, December 29, 2013

Mandarin Garnet

I haven’t written much about Mandarin garnets because I don’t really like orange as a color, and so I’ve ignored this gem for a long time.  But now I think I didn’t do it justice.

Spessartite, the garnet group that Mandarin garnet falls under, has only been on the gemstone market for a little over 10 years.  Although tiny amounts have been found in Germany, California, and Sri Lanka, among other places for a couple of hundred years, it was so rare that it was considered a collector’s stone.  Marketable quantities have only shown up in Namibia, then Nigeria and Mozambique in the last decade or so.  In 2007, there was a find of facet grade Spessartites of beautiful bright color near the town of Loliondo, Tanzania (it's basically a location in the bush, some 10 miles off of a dirt road in the middle of nowhere).  A gemologist friend of mine travelled there a few years ago and got some nice crystals – a dangerous journey that necessitated an ample supply of weapons for security.

Die Lagerst├Ątte Nani
Spessarite "Mine" near Loliondo, Courtesy of Jentsch Mineralien
The color of spessartite ranges from a light orange to a deep reddish brown, with the bright and pure neon-color oranges being the most desirable and the most expensive.  The trade has termed them “Mandarin” garnets.  Initially these garnets came from Namibia, and then Loliondo, Tanzania.

Here's a sampling of my purchase, the stone with the best color is the second to the left
Like most garnets, Spessartites are mostly smaller in size, but 1-3 carats are available, 5 carats and above are rare.  While a brown Spessartite under 1 carat can run as low as $20/ct, a well cut Mandarin in that size can cost 10 times that much.  Recently prices have been on the upswing because the mine in Nigeria is no longer up and running.  Originally, prices were low but world demand drove them up very quickly.  As a result, smart dealers that had overbought at the time stashed their parcels away.  Indeed this was a good move, because after staying steady for a few years, prices have recently doubled because supply is now dwindling.  This is in part why I acquired some pieces.

Design wise I was surprised how well the bright orange looks in rose gold, and in particular when pink gems, like mahenge spinel and pink sapphires, are added into the mix.  I also love the combination of red, orange, and yellow (i.e. yellow sapphires and Burma spinels).  Mandarin garnet, as opposed to pyrope garnet, also has excellent performance in incandescent light.  In fact, I find that they look their best when the light does not hit them directly, but when it is subdued.  Then a good quality piece can almost look neon-orange, despite the occasional tiny white inclusions that are called “sugar” in industry.  That neon color is what drew me in the most.  Extra fine Mandarin ovals can look more orange from one angle, with flashes of reddish orange from another angle.  It’s really quite beautiful.

Mandarin Garnet ring with Burmese Pink Sapphire
This not-quite-red yet not light orange color is extremely rare.  I’ve seen large parcels from the Loliondo mines with perhaps just one or two stones that looked like that.  In fact, I went through every parcel at my gem dealer’s office in the smaller, more affordable size, and pulled out all the most neon pieces I could find.  These days, most mines no longer produce that color at all.  Recent reports indicate that only low quality rough is being offered in Nigeria, and one source has told me that because of political tensions among locals, the Nigeria mine is no longer operating now.  And so it goes until we find some more elsewhere on the African continent.  

Sunday, November 24, 2013

The Intricacies of Gemstone Pricing

Gemstone pricing can seem to be all over the place. Quotes on the same stone fluctuate depending on the seller, the buyer, and even the context: Internet sales vs gem shows, U.S. vs overseas. But despite appearances, there is logic to gemstone pricing, and making the right quote - the quote that yields a transaction – can be considered an art.

To start with, there are a number of different pricing levels that are below retail.

1. Rough bought on location. This is the cheapest way to buy but even rough is pre-sorted and you have to understand what you are looking at. After cutting, rough loses an average of 80% in weight.  Gemstone cutting can be $1 or $5 per carat, finished goods. Cutting grade rough for fine gems like sapphire is quoted per gram, and for cheap stuff like amethyst it is quoted per kilo.
2. Cut gems bought on location. In place like Tanzania or Sri Lanka many gems are cut before they leave the country (in Sri Lanka this is the law). But strangers are not likely to get good prices.  Buyers and sellers have established relationships and introductions are needed. New buyers can be tested for their knowledge of prices. If a buyer haggles when a low quote is made, the seller may refuse to work with that buyer in the future.
3. Dealer pricing.  Finished goods make their way to the U.S. (mostly New York) via a middle man who sell only to gemstone dealers at a markup.  Some U.S. dealers also traveled directly to India, or they are connected to gem dealers in other places in the world, or they travel to buy on location. They buy at dealer prices, and if they sell to each other, they sell at dealer prices with a small markup.  Markups at this level average 30%, or less if it’s dealer to dealer.
4. Wholesale pricing. Gem dealers then sell their wares to independent designers and jewelers or jewelry chains. A wholesale buyer has to have a business license or a tax ID so they can be exempt from sales tax. The markup here is also around 30%, but quotes can be higher or lower, depending on the relationship.  Repeat business is often rewarded with reasonable markups.

What about retail pricing?  There are several levels of retail as well. A gem lab calculates a retail value at 30% above the most recent wholesale pricing tables - these tables average out wholesale prices across locations in the U.S.(with N.Y. being one of the cheapest locations). This is not related to store retail which is usually higher. It is also not related to the retail price of finished jewelry: material cost plus cost of labor x4 (x2 for wholesale and x8 for high end stores).

Against these basic standards, several additional factors can affect pricing.

Mandarin Garnet Parcel, with Two Unheated Zircons Thrown in for Contrast
1. Urgency. Some people need their goods right away. They have a custom order that is already paid for, they have an impatient buyer, or they have an impatient personality. When several dealers on 47th street get "calls" for the same stone (i.e. a 4 carat sapphire for an engagement ring), it's considered a "strong call". Then everyone smells money and the prices go up. So even of one really needs to buy, it is best to proceed in a relaxed manner.
2. Time spent with the seller.  Some buyers spend hours at a gem dealer’s booth or office, and that ties the seller up.  Many sellers need to move material quickly (they too need to calculate their pay by the hour).  Their booth or office may be small and so they cannot help several people at once.  The same thing happens on the internet.  If a buyer needs a lot of photos and has a million questions, it can take hours to negotiate a deal.  Price levels have to reflect this, and they are one reason why many gem dealers won’t – or simply can’t – deal with the general public.
3. Trustworthiness. You wouldn't believe how many buyers on 47th Street memo out stones and don't pay, or don't pay on time, don't return the merchandise, and string along sellers. "Check's in the mail." Uh uh.  Checks do bounce. Even certified checks! Credit card purchases are disputed after the buyer has made off with the goods.  If you are a “serious buyer” – ready to pay, and people know your checks go through, and on time, you will get far better quotes.
4. Haggling. You may get away with it the first time, but when, after seriously haggling down a price, you return to the same gem dealer for more, you'll find that all the prices have suddenly increased: If the dealer expects you to haggle, he has to start with a higher base price.


Tsavorite and Mahenge Spinel Cabochon Parcel
Of course now you are wondering price level I buy at.  Most of the time, I get dealer
prices.  When I first started buying on 47th Street, I knew nothing whatsoever about gemstone pricing, but I discovered after a while that everyone offered me good deals (this really wasn’t obvious to me at first).  When I asked a gem dealer friend about this, he said “it’s because you pay.” I thought that was a ludicrous suggestion.  Don’t people usually pay when they buy things?  Now, a few years later, I realize he was right.  Gem dealers must have thought I was from Mars.  Owing money, wasting someone’s time, and haggling all make me extremely uncomfortable.  Dishonesty doesn’t come easy to me – I can never think of a good lie fast enough, not even white lies like: that dress doesn’t look bad on you – so on occasion I get into trouble, even with my friends.  But as it turns out, Martians can do very well among gem dealers.



Sunday, November 3, 2013

Tricks and Tips for Designing in CAD

As you see more and more of Brandy’s CAD (computer aided) designs in my shop, I thought it might be time to explain the design aspect of the process a bit more.  This will also help you if you are interested in placing a custom design order that requires CAD.

When do you need CAD?  CAD is extremely useful when you don’t want to make a design from scratch in metal, and especially when you have an idea that is more complicated, like my halo and multi-stone rings.  Imagine how long might take to make all those tiny little prong settings, for instance.  CAD is also useful when you have a specific stone and can’t find any stock settings that work.  But CAD doesn’t work well for flowy designs, and the geometry for certain shapes is incredibly complicated.  The more curves, ridges, settings, the more detail in other words, the longer it takes. 

Wedding Band CAD with Dimensions
A CAD ring will indeed take several hours in design work, or even more.  A simple setting might only be 30 minutes, but if you’re designing a complicated gallery for instance, adding all those curves and finalizing the dimensions can take an afternoon.  After that, the CAD model has to be “printed” in plastic , then cast in base metal, then molded, then again cast in the desired metal.  You can also go straight to casting from your plastic model, but if you then need another one, you have to print again, and printing can cost up to $100.  3D printers are expensive, and the printing process is slow.  Long story short, you are looking at a few hundred dollars before you so much as have a first casting.

Since CAD works on a mathematical basis, you need all your dimensions pretty well worked out before you can begin, and you may need to refine them as you design, or go back and forth with your CAD person.  This includes inside diameters of bezels, thickness of bezel walls, prongs, etc, for each part of your ring.  Brandy, who is very good at this, often supplies these after I give her the stone, or stone dimensions, the basic ring dimensions and my drawings.  She knows how deep a setting has to be to fit a stone, what wall thickness is required for a bezel, how much space to leave between stones, and other things you’d never think of if you haven’t done this a lot.  Nevertheless, sometimes Brandy and I have to sit together for a couple of hours and hash out specs as we try them out on the screen. 

This Cluster Ring is not Done Because We're Working on the Gallery , Often the Hardest Part
You also need to have a good sense of imagination, because a lot of time a model looks one way on the computer, another way when it is printed and cast.  One of my new rings ended up too heavy on the top, and the shanks were too thin to make it look balanced.  And when you plan to add stones in a beaded or burnished setting, you need to be able to visualize how the piece will look when it’s finished, because on the screen, and even in the silver casting, it will just be an empty canvas.

My Victorian Flower Earrings Before Setting

A Finished Design with the Same Setting
Sometimes other impracticalities intrude that you don’t think of.  Your finger is too small to support several stones in a row, or sizing will be an issue later.  Eternity bands have to be done for each size for instance, and in each case you have to change the design a little.  You also can’t just make a design bigger or smaller because you will want to shrink just certain aspects (i.e. the center setting but not the shank).  This means that certain changes in size necessitate many other changes down the line. 


               Finally, you have to think about practical aspects during casting and printing.  The ring I made (below) cannot be cast in one piece because the silicone could not get underneath the ring.  So Brandy made a gallery, lifted the top and made two designs that have to be assembled after casting.  Also, since you can’t cast in two metals at once, any two tone designs require two models that have to be fitted together and assembled.  

Shank is Too Narrow (The Thing on the Right is the Sprue)

Can't Mold in One Piece

Top is Too Thick, Needs a Galllery

Sunday, September 15, 2013

Breaking an Apatite. Or: How Observation can Interfere with Experiment

So I had the brilliant idea of taking snapshots while my setter, Pierre, set an apatite into my new silver halo ring.  Dark blue sapphire outside, turquoise center, it was going to look fabulous.  Pierre has some very fancy setting equipment.  At his bench there is a huge microscope with very strong lighting that costs several thousand dollars, surrounded by lots of other smaller gadgets.  I guess you need that when you routinely set expensive gems.  Luckily, my apatite had only cost me about $20. 

Ring Inside Ring Holder
First, Pierre carefully clamped my ring into a ring holder, cushioning the outside of the shank with tissue so wouldn’t get marred.  The ring has to sit tight in order for the pressure from setting not to dislodge it.  Then Pierre separated the double prongs.  During casting, prongs that sit close together often have metal in between them, and it is cut apart with a separator disc.  Then the prongs are shaped into claws and the seat is drilled: that’s a little groove on the inside of each prong where the girdle of the gem will rest.  I like my gems set low, and the apatite fit perfectly into the opening.

Separating the Prongs
Unfortunately, the lighting of his microscope was so strong that my iPhone couldn’t cope, so I asked Pierre to lower it.  Which he promptly did, but not without mentioning that he could no longer really see what he was doing.  I should have taken that as a cue.

Having placed the apatite into the ring, Pierre proceeded to push the prongs over the gem with his metal bezel pusher.  

Pushing the Prongs over the Stone
As a final step, he rubber wheeled the prongs.  This means sanding them down with a soft rubber disc so that the places where he marred the metal with the bezel pusher – something which is unavoidable – are filed back out.  Normally this is the tricky step because you don’t want the rubber wheel to scratch the stone. 

Rubber Wheeling the Prongs
As it turned out, in this case, the moment during which the little apatite incurred major damage was minutes earlier.  It happened shortly after the light was turned off in order to accommodate my iPhone.  Ahem.  The third photo shows you approximately when Pierre chipped it. 

Long story short, my apatite didn’t live.  And now there’s a pretty tourmaline in the center of that same ring.  So that’s how it goes.  Apatite is risky business.  With a sapphire, this would probably not have happened.  But from now on, I’m not going to ask Pierre to work in the dark! J


Chip in Girdle on Right Next to Where the Prong Would have Been (Plus Scratches You Can't See)

Friday, September 6, 2013

Working with Cabochons and Rose Cuts

If you are used to working with only faceted stones, you’ll find that cabs and rose cuts are an entirely different animal.  Very little of what you know transfers over to the non-faceted gem world.  Cab pricing and weighs are different, they are judged on a different scale, and most commercial settings don’t work.

First, be aware that cabs and rose cuts are not usually clean gems.  The facet grade rough is – well – faceted, and cabs are the next grade down before rose cuts and then beads.  Cabochon material is therefore rarely as clean as faceted stones.   The quality often ranges from very good (near facet grade) to very poor (totally dead and opaque).  Obviously, I don’t recommend the latter.  Cabs don’t have brilliance either, rather, when set right, they glow, despite inclusions.  Cabs usually rank better in terms of glow than rose cuts because the facets of rose cuts don’t let the gem be as bright.  And of course the term “window” doesn’t apply because to not have window, you need back facets.  Technically, therefore, all cabs and rose cuts have window. 

Spinel Rose Cuts
When you buy cabochons, you can expect a lower per carat price than for faceted stones, but you also need to expect them to weigh more.  On average, cabochons weigh twice as much as faceted stones in the same size.  The exception are rose cuts, because they are flatter and the top facets remove extra weight.  The facets hide flaws, however, so your expectations of a rose cut should be lower than that of a cabochon.  Rose cuts usually weigh about the same as faceted stones.  Often, though, a high quality cab and a low quality faceted stones can come out the same in terms of price.

Finding the right setting for cabochons can be challenging.  Even calibrated stones often do not fit the settings that are fabricated for their size.  Many are too high so that the bezel wall doesn’t fold over right; or they are too low so that the stone vanishes under the bezel wall.  Yet others are slightly too big or too small – the latter applies to rose cuts in particular.  The smaller the cabochon, the more problematic it is if it doesn’t fit right.  So when you choose cabs, watch for high dome and low dome, as the terminology goes.  If you have a bezel already, bring it with you when you buy the stone and see how the stone looks in it. 

Round Commercial Bezels
Add to that, that many cabochons are not calibrated in the first place.  So you have to expect to be making the bezel by hand.  This is even more the case for rose cuts, which are often cut in irregular shapes, just following the natural lines of the material.  The expectation is that for either, you will make your own setting, or have it made. 

When I make bezels for cabs and rose cuts, I usually do a closed back.  I find that many gems look washed out when there is no metal behind them.  The light simply passes through them and that dulls the color.  The exception, for me, is when I channel set cabs for earrings, because then I like the light to pass through.  A ring or a necklace has your skin behind it at all times, and that doesn’t help the stone reflect out.  In earrings, that is not a concern.

Square and Oval Cabochons, Cabochon Bullet



Friday, August 16, 2013

Gemstone Etiquette 101: Ten Gem Buying Tips

Yes, there are rules when you buy gems.  And if you don’t know what they are, you can easily offend or, much to your disadvantage, drive up the price at which you buy.  These ten tips will save you some grief, and hopefully also some $$$ at your next gem buying spree.  Remember also that strict rules are established because it is easy to cheat in the gem business.  Trust, therefore, is everything.

1. Gems are priced by the parcel or individually.  Large and uneven parcels are the cheapest, small and well matched parcels cost more.  Individually priced gems cost the most.  If you have the time, you can save by selecting from parcels, but be sure to communicate that you intend to select by asking for per carat price for selection first (unless, that is, the trays are openly displayed for you to pick from them).  And yes, prices are usually quoted per carat.

2. You can ask for a loupe, most gem dealers carry them.  Check the table and back for scratches, and rest the stone between your index and middle fingers to look for window.  Move it away from the dealer’s light source to see how it looks under darker lighting conditions.  For expensive stones, ask if you can take the gem into standard daylight, i.e. near the window.  If you drop the stone, look at listen: don’t take your eye off it and listen to where it bounces and how often.  The little buggers have a way of vanishing.  And don’t leave the booth while the dealer is looking.  You dropped it, so you have to help him find it!  You may also have to pay for it.

3. Don’t give the store away: if you’re asked for your budget, hedge or say you don’t know yet.  If you’re asked to name your price, ask the dealer for his price instead.  Gem buying can be like playing poker, where you don’t show your hand.

4. If you like a stone, don’t jump up and down with joy, especially if you forgot to ask for the price ahead of time.  And if you hate the stone, don’t insult the merchandize by saying it is not good.  Dealers are proud of their inventory and can think you don’t know what you’re talking about (and just maybe, you actually don’t).  Just say “not for me."   

5. Bargaining is tricky.  Many prices are fixed.  But you can say that a gem is a little out of your budget or more than what you were hoping to spend.  Then let the dealer come down in price if he thinks he can, or wants to.  You could ask if there’s anything the dealer can do on the price.  Personally I don’t.  I just say it doesn’t work for me, that I might have trouble selling the merchandize at my markup.  Then it’s the dealer’s turn to see if he can make a better offer.

6.     If you can’t estimate weight by stone size, have each gem you are considering weighed and priced before you make your final choice.  I have seen hasty gem buyers annoy dealers by piling lots gems onto their selection trays to buy and then putting most of them back when they hit the scale.  This wastes considerable time and if the gem show is busy, other potential buyers have to wait for you.  It is best if you memorize some standard sizes and weights before you start shopping (you can use a diamond table and add 20-30% for extra weight and bulky cutting).  Or ask the dealer to estimate, many can do that very well by just looking at your tray.

7.      Not all treatments are identified, in fact, many gems are loose on trays or in bags and just have an ID tag that tells the dealer how to price the gems.  For emeralds, sapphires and rubies, always ask about treatment.  The word “natural” is not helpful in this context, since it is used to distinguish synthetic and lab created material from the genuine article.  So a natural gem can be treated.  Some gems are always treated (i.e. London blue topaz).  You should be familiar with some of the basic ways in which gems are treated, but you can always ask, “is it treated”?  This obligates the dealer to disclose.

8.      Neither a price quote nor the agreement to buy should be retracted.  That’s why it’s important that the dealer knows what he is quoting you and how many carats.  His (or her) quote is good once it is made.  When you agree to buy, that counts as a verbal contract.

9.      In the gem buying world, there are no refunds or exchanges unless they are agreed upon ahead of time.  Buyers can switch out gems and return a fake, or they can scratch a stone, i.e. by trying it in a setting, and then return it scratched.  Sellers protect themselves against this with strict no return policies.  If the seller knows and trusts you, you can memo out a stone, either against deposit or for free.  During this time you are fully responsible for the stone, and if you lose it, you have to pay for it.  If you do not return it within the agreed upon time period, you can lose the future privilege to memo out a gem.

10.   For good pricing and to establish trust, introduction by another buyer or gem dealer is helpful.  If someone sent you, mention their name.  You can also recommend someone, but remember not to recommend people you don’t trust or know, because if an expensive deal goes south after you have introduced the respective parties, you can get blamed. 

Selection of Trays at a Gem Show



Wednesday, July 31, 2013

What’s a Gem Show Like?

In one word: overwhelming.  I was at the Jeweler’s Association Summer show at the Javitt’s Convention Center last weekend.  I had a long list of things I needed and a smaller customer wish list.  I had a good night’s sleep and got there 5 minutes after they opened.  Eight hours later, I was completely wiped out. 

The show I went to is mainly for jewelry but the AGTA pavilion has about 50 gem and bead dealers whose stuff you can look at.  Some have their gems in little pre-boxed parcels, others have open trays for you to sift through and pick what you like.  Prices are usually on the trays, but it is good if you can estimate weights because otherwise you will be surprised about your tab when it all gets weighed out at the end.  You may do what so many do when they overspend: ask some of the gems to be put back.  Gem dealers are used to it but that doesn't mean they like it.

Selecting from Gem Trays

I buy a lot of boxed gems but I also spend a significant amount of time selecting individual or pieces from little bags and trays to match for earrings.  I spent 90 minutes in one booth and I didn’t even realize the time!  I also bought a bunch of beads.

The most interesting find for me, but not affordable at all, were the Paraiba tourmalines in the photo below.  The 3mm melees started at $1200/ct – my price!  More than diamonds.  Sapphire prices have gone up again, I bought more or less what was left at the price of February from the dealer I know that doesn’t change the old prices on his gem boxes.  I found some nice multi-color 5mm round Ceylon’s (heated) that I will put up on Etsy.  And some peachy colored Morganite, but heat treated as well. 

Paraiba Tourmalines
Prima gems had a ton of beads that were fun to look at, and some carved rough.  I found a few pieces of nice richly colored heated blue zircon with them and some top drilled beads that I will make into earrings with pearl cups.  All in all, the show was a success for me, but there were some things I couldn’t find: good emerald, nicer green sapphire, pink tourmaline.  The latter has about doubled in price since I looked last, so I’ll have to check with some dealers in the city and look through old parcels.  All tourmalines have gone up but the pinks especially.  

Prima Gem's Bead Table

Jaimeen, Sukrita and Geoff from Prima Gems

Sunday, July 14, 2013

Precision Cuts: Are they For You?

If you are addicted to gems, you will soon find yourself getting attracted to precision cut gems – gems that have unusual shapes and more intriguing faceting patterns.  But setting gems like these is a whole other story. The cutter’s objective – bringing out the best of the gem – often conflicts with jewelry design and ease of setting.  So before you sink all your spare change (and then some) into a precision gem, keep these pointers in mind.

If you don't want to spend a ton of money having a custom setting made, you need to stick to shapes for which commercial settings are available. Prong settings are come in round, oval, square, marquis, pear, pear and emerald shape, as well as some baguettes. For other shapes you have to adapt an existing setting. Octagons and hexagons can go into round settings, cushions fit in into squares. Some rectangular cuts can fit into emerald settings. Prong settings are forgiving and can tolerate a fit that is not exact. Figure a tolerance level of .5mm, but buy the setting .5mm larger if you’re not sure. Undersized prong settings are often too shallow and the prongs will not fold over the stone.

Bezels have to fit precisely, with at best .01 mm to spare. There are no commercial bezels for rectangles or baguettes. Otherwise they are the same as prong. Cushions do not fit into any commercial bezels.

Also keep in mind that colored stones tend to be deeper in cut than diamonds because they are cut for color optimization. The deepest and bulkiest cut is step cut which is common for sapphires. They have a heavy belly, as we say. Portuguese cuts are also s bit bulkier. So you should ask about the depth of a stone if that is not listed. Most settings are made for brilliant cut stones. The depth of a brilliant cut is 65 per cent of the width and that’s the proportions for which most settings are made. For prong settings, this means you may need longer prongs. For bezels you need depth or else the stone sticks out the back once it is set.  Remember that for a ring, the back of the setting has to be rounded out, so you have to subtract a couple of mm.

Ouch - this will hurt

Another point to bear in mind is that girdle thickness is an issue for straight bezels with a pre cut bearing wall. The gem might "spill out" and the bezel walls will not fold. An alternative is to have the jeweler buy tube (which comes in round, square and oval), and saw off a piece in the right length to fit the overall depth of the stone, then drill the bearing wall.  But that means that the jeweler has to buy tube and cut it to size, which can cost more. 

Bezeling doesn't work well with a round stone has corners cut into the girdle. The only bezeling option is to cut all the corners into the bezel itself and then hope the pressure from setting doesn't bust the gem. But there are no pre-cut bezels for stones with corners except for princess and emerald (there certainly aren't any for octagons). Also, that kind of setting is beyond the expertise of most setters – it hardly ever comes up so nobody gets a chance to practice.  And you don’t want your gem to be the guinea pig.

Finally, bezel setting implies that more pressure is applied to the stone than in prong setting. Especially when the bezels are thick, because thick bezels are literally hammered around the stone with a miniscule “jack hammer.”   Many gems cannot handle that, especially when the bezel is gold, which is much harder than silver and requires even more pressure. Also, it is preferred that the gem doesn’t have corners.  Hammer setting emerald cuts, for instance, is extremely difficult. Princess cuts are nearly impossible. One wrong move and the corner chips or causes a crack that goes through the entire gem.  Some gems, i.e. tanzanite, can break straight through.

This bezel is for hammer setting, the side view is the same as the one above
In summary: think “prong setting”, avoid gems with corners, avoid setting soft stones in hard metals, and run with cuts for which there are existing settings. 
Amazing but at best a pear prong setting works (the wire will show because it's per shaped, not trillion)

This is gorgeous but it will only fit into an emerald cut or oval prong setting


Sunday, June 30, 2013

Gemstone Underdogs: My Favorite Under-Appreciated Gems

I've been buying beads and gems for about six years now, not as long as other addicts, but I buy every week, and I buy direct.  I rarely buy online.  Living right outside NYC provides me with a lot of opportunity to touch stuff, to loupe it, to see how it feels and acts under different lighting conditions.  I have hardly seen everything, but I've seen a lot.  And I think there are still gems out there worth having that haven't gotten the attention they deserve.  Here's a short list.

My Favorite Gem Underdogs (in no particular order):

1. Chrysoberyl: this gem belongs with the family of alexandrite, but it is more durable with a hardness of 8.5 - which even beats corundum.  The yellow color is really pretty, with the nicest specimens being lemon yellow.  The browns are so-so.  When cut well, Chrysoberyl is very brilliant, crisp, and it is still reasonable in price.  I've seen them as low as $20/ct on the web for the smaller and more brown or very light yellow varieties.  But remember that even for Chryso's, the 1, 2 and 3 carat imply shifts in price.  The cat's eye chrysoberyl is also interesting, but in large sizes it is very expensive.  I prefer the faceted gems.  Right now much of Chrysoberyl comes from Tanzania and Sri Lanka.  I like the Tanzanian gems, which are usually brighter, less brown.

Chrysoberyl Lot, The Brown in the Corner is Sri Lankan, the Center is Tanzanian

2. Merelani Mint Garnet: some internet forums say it's just a "lesser" form of tsavorite, and the term "mint" is pure marketing to drive up the price.  False - and true.  The term "mint" for the color is new, and mint garnet is Tsavorite.  But: Merelani mints have to come from the Merelani mines.  I've seen other Tanzanian mints, and they're not as nice.  The Merelanis have no secondary yellow compared to standard light colored Tsavorite.  Right now Merelani mints and Tsavorites are priced about the same, with Tsavorite topping mints in the larger sizes.  Merelani mint production is insanely tiny, and most lighter Tsavorites don't even come close in terms of color, crispness, and beauty.  I'll take a mint anytime over a Tsav.  Tsavorite production is down as well, so I expect both of these to only go up in price as availability dwindles.  I don't think you can go wrong buying a nicer specimen for your collection.

Merelani Mint Garnet Mix, The Nicest is Center Front, 5.8mm, Portuguese Cut
3. Color Change Garnet: forget alexandrite.  Just totally forget about it.  Birthstones are decided by the American Jeweler's Association for marketing purposes!  Color change garnet - the nice, high quality stuff - has a better daytime color.  The most beautiful pieces come from Tanzania and they're a strong teal color (Madagascar is another origin but I prefer Tanzanian).  Some CC garnets are also forest green.  The ones with brown, peach and red daytime colors are less valuable.  Most CC garnets have complete color change to a strong reddish purple, whereas most alex on the market today has only a faint change.  Alexandrite is murkier in daytime color, probably because it is more included.  One carat of the nicer stuff can cost me $5000-10000, so there's obviously no room for markup.  And "Russian" alex is just lore.  That hasn't been produced in over 100 years and production was never high.  Lots of stones marketed as that are fake.  Meanwhile, you can get a 1-1.5 carat cc garnet for about $600-800 per carat (prices change every half carat).  CC garnet should be clean when you buy it, or very close to it, and try to avoid grey mask (lots of the larger stones have grey mask).  CC garnet larger than 1.5 carats is very rare.

Matched Pair Color Change Garnet, Tanzania

Color Change Garnet, Possibly Madagascar

Tanzanian Color Change Garnet Pair in Incandescent Light, the Color Change is Actually Stronger
4. Zircon: low zircon, high zircon... I've never heard that language used among gem dealers, so let's concentrate on what I think matters.  There are lots of origins, I'm not aware of one being better than another, except Cambodia for blues, but that production is finished or nearly finished as far as I know.  Zircon is clean, very sparkly, and the whites, peach, red, brown and honey colors are very reasonable.  I prefer white zircon over any other white stone except diamond.  In the smaller sizes, it might be $20-30 a carat retail. You can heat it at home (see my blog entry). Use the cooler browns and red tones to make peach or white, stay away from the honey colors, they fade back to honey over time.  The blues, today, are exclusively heated.  You have to find old material for unheated and most labs won't be able to tell you either way, they just assume heat.  Some blues fade over time but they can be reheated.  In terms of price, blue zircons cost more in the larger sizes, and the more saturated ocean blue tones are also pricey.  The lighter smaller, pieces are about as cheap as the other colors of zircon.  So anything under 1/2 carat shouldn't cost too much.  The rarest color zircon, as far as I know, is green, with chrome and forest greens being the most uncommon among the greens (most are olive or a light green).

Rare Green Zircon
I have other favorite stones that are not very expensive: sphene, kyanite and apatite are three of them.  But none are very durable (sphene is the best among this list), and they're hard to set.  Apatite can't be pickled, and I'd hesitate with ultrasonic.  Kyanite is liable to split in half lengthwise if the jeweler applies too much pressure folding the prongs (and he should apply pressure so the stone doesn't fall out!).  That limits the options of what can be done with these gems, and it means that if you wear them in jewelry or don't keep them separate in storage, they will chip and crack over time.  An unsuspecting jeweler who offers to clean your pieces might destroy them.

Wednesday, May 29, 2013

Should This Gem be Recut?

The gems I offer on Etsy do run the gamut: some have amazing cutting that brings out the absolute best of the gem, others are look more like someone was still practicing on them.  Wouldn’t I be better off having those recut?

There are pros and cons to this question.  To me, there are three important factors to consider when asking myself if I should recut a gem: price, outcome, and what type of gem I'm recutting.

1.      Price: small melee size gems can be re-cut by machine, and that’s how it’s done nowadays.  That’s relatively cheap but of course the quality of the individual gems is not considered – or which way to cut it.  When I buy old material that has seen better days I occasionally have this done, but only if I think I can’t reuse the material as is. 

Re-cutting a larger gem, by contrast, takes time, expertise, and cash.  A good average time frame for a re-cut is one hour.  Prices vary, in NY I pay wholesale, which is about $50, but I have to tell the cutter exactly what I want, and many cheaper cutters are not that good, so a re-cut doesn’t always improve the stone.  Also, stones can break during cutting, especially the softer ones.  Retail pricing for re-cutting is about $100-150, or more.  When I have gems re-cut I usually send them through a gem dealer friend to his cutting factory overseas (India or Tanzania).  I pay $3 per carat, give or take, but it can take months to get the gems back and I can't specify any shape.  

Also: diamond prices are different.  Diamond and colored stone cutting are not the same in terms of equipment and training, so the two trades are separate, and diamond cutters charge more.

2.      Outcome: re-cutting a gem means weight loss.  If it just has a scratch and I need a facet fixed, it’s maybe a few points (and costs only a few dollars).  If I have a nearly unusable pebble, it might lose half.  The average weight loss for facet rough is 70-80%.  Also, you can’t always cut out an inclusion, but sometimes you can make it less visible.  Recutting, when it’s done right, can drastically improve brilliance, especially when you add facets (i.e. by going from a step cut to a Portuguese cut).  Windows can be closed by changing the angles of the facets.  And color can be improved too, sometimes unexpectedly so.  But each stone is different, and there are no general rules for predicting outcome.  On Etsy there are some cutters that allow you to send in photos of your gem, and they can give you a rough idea of what improvements are possible.

3.      Not all types of stones should be recut.  I don’t recommend it for most sapphires, for instance.  Ceylon sapphires, by law, are cut in Sri Lanka, and while that cutting is not always superb, Sri Lankans do know how to pull the color out of their sapphires.  Ceylon sapphires are often very light, and there’s just a little bit of color in the culet which distributes over the whole stone and makes it look dark.  If you cut away the bulk in the back, i.e. to make it fit better into a setting, you will lose the color – so the much criticized “native cut” that’s supposedly adds nothing but weight to a gem can have definite advantages.  The standard sapphire step cut, which has shallower angles, additionally preserves color. 

Emeralds are also hard to cut, and they can crack – many cutters prefer not to cut emeralds for that reason.  Nowadays much of the emerald material from Colombia is very light, so it’s hard to bring out the color without also adding depth. 

In general, my rule is that old mine material should be left alone unless it’s really worthless as is, or tiny.  This means that I often have to set bulky stones into settings made for diamond cuts.  So the prongs can be too short, the stone might stick out the back of the bezel, and it can move during setting because it doesn’t properly sit in the bezel, which increases the risk of breakage.  Setting colored gems, especially oddly shaped ones, is not for the un-initiated, that’s for sure.  (It’s yet another reason why I don’t accept a customer’s stones for setting.  I never know what I’m gonna get and if what the customer wants is even possible.)


Spinels from Same Lot: the darker one has been recut




Saturday, May 18, 2013

Where does my Tanzanite Come From?


It is rare that one gets much insight into the actual method by which gemstones arrive at the gem dealer’s booths in New York, unless, that is, one knows buyers who shop direct – “from the mines,” so to speak.  I know two people who do just this: one deals in the crystals that are displayed at mineral shows, the other sells gem quality pieces.  The latter goes through his uncle, who is a gem dealer in Tanzania, the former, Jochen from Jentsch Minerals, is a geologist that has seen the process down to inside the mine.  Jochen, who has a Masters Degree in geology and mining, has spent decades travelling back and forth between Africa and Germany, his home country.  He consults mining operations by writing survey reports, explaining where they should mine and how.  His childhood dream was to cross the Sahara desert, and he saved up for the trip by collecting and selling minerals while he was still in college.  Three months he spent on the road, starting somewhere in North Africa and ending up in the Congo.  It might have been a shorter trip but his vehicle broke down in the Sahara and he had to wait for someone to pass by and give him a ride.  He waited three weeks.  Jochen speaks German, English, French, Spanish, as well as Swahili, the local language Kenya, Tanzania and Mozambique, among others.

Jochen from Jentsch Minerals
There is actually only one Tanzanite mine in the world, located near Mount Kilimanjaro in Tanzania.  It is divided into four parts, named Block A-D (though the individual “mines” also have local names).  The C block is commercial and high-tech, it belongs to a South African Company called Tanzanite One.  It is high security and off limits to any outsider.  The B and D blocks are reserved for small scale local miners that work in groups, staking claims that look small on the surface but that reach hundreds of meters underneath the earth.  There is no regular pay check for miners – they receive only food: rice, dried fish, nothing much else, but they can survive.  They sleep outdoors, on trees (yes) and in simple huts.  All the rough that is found is collected by the stake holder who owns and manages the mine.  In small parcels, it is sold off to dealers, or to others that have the right connections, like Jochen.  The price of each parcel is negotiated between the buyer and the seller – often with the help of a gem broker (who, as opposed to a gem dealer, does not own any gems but helps facilitate a transaction for a fee).  The proceeds are split among the miners.  The hope of any miner is to find something truly valuable.  For most of them, that dream never comes true.


Mineral Display - Jentsch Minerals
But at least some of the money that is made off Tanzanite makes it back to the local workers this way.  And to the government, of course, which collects a tax on all the material that is exported.  To take rough out of Tanzania, it is packed up into tin boxes which receive a special government seal that indicates the tax is paid.  But there is also a second seal, which is in the hands of the more local authorities.  These must be paid what we’d call a bribe because it’s not official, yet it is understood that without the second seal there is no exporting the goods.  The “bribe” – which I bet in America would just be called a municipal tax (but this is not America), is again split between locals, and it’s another way for some of the money international buyers make off of the goods stays in Tanzania.  It is, perhaps, the only way, and as I see it is only fair, considering the markup Tanzanite enjoys once its cut, graded, and finally ends up in the hands of the American consumer.

And that is how the Tanzanite comes to me – with no middle man – and it provides me with some insight into the process.  What we pay the locals is not fair by our standards, but I know that it means survival to those who climb ladders leading hundreds of meters underground, who get killed by heavy rains and floods or by the occasional underground shootings that take place when lines between stakes are crossed.  Who work in rags and with poor equipment, eat dried fish and rice, not being able to predict life beyond the next corner.