Monday, September 27, 2010

On Cutting a Stone: Chronicles of a Tsavorite

Some of my fellow jewelers have been asked if they cut their own stones.  And a friend of mine once wondered if all the stones I buy are cut specifically for me.  The answer to both questions is “no.”  For one, becoming a lapidary – a stone cutter – takes a lot of practice, and gemstone cutting is best left to those who specialize in it.  Secondly, cutting takes a lot of time (and hence money).  A tiny 1mm diamond, for instance, can take an hour to cut.  No wonder, therefore, that most small stones are not cut in the U.S.  A small amethyst, for instance, can wholesale for just a few dollars.  Meanwhile, a good N.Y. lapidary can charge $50 an hour or more for his skill.  Most of the stone I own, therefore, are cut in India, where this is an old family trade.

This raises a lot of issues about ethics and economics, doesn’t it?  Yes, we all profit from cheap labor.  There are no two ways about it.  The only mitigating factor is that the wage a cutter gets in India – which is about $1.00 per stone – buys you a lot more there than it buys you here.

Does it ever make sense, then, to have a stone cut in N.Y.?  That’s a “yes” if it is a larger diamond. N.Y. has some of the very best diamond cutters in the world.  It is also worth re-cutting a stone for repairs.  Lastly, it is worth doing, and even cost effective, when the stone is large or rare.  If you know how to pick from rough (ok, that’s not easy), or if a gemstone dealer who has rough is kind enough to pick a good piece for you, you can have it cut to your specifications, and you may find yourself the owner of a unique gem that nobody else has.

Speaking of kind persons, my gemstone dealer D., who is also a lapidary artist, picked out a beautiful clean piece from his tsavorite rough for a little demo.  As those of you who follow my Etsy listings know, it’s been very hard for me to get tsavorite.  D. only has rough, and would have to ship it to India to have it cut, which would take months.  I’ve seen other parcels on the street, but they’re prohibitive in cost.  I know of one dealer in Jersey who has his own rough cut in India (rather than purchasing finished stones), and he occasionally has small parcels of tsavorite.  I’ve bought some from him at a show last spring but sold it immediately.  I bought a matched pair at a later show but my setter lost one (yep, it happens).  I’ve emailed the dealer without much success (“we don’t have any right now,” “we’ll ship soon,” “we’ll be in touch”).  Sigh. 

Tsavorite comes only out of Tanzania and Kenya, where it was discovered in the early1970s, and because it has a wonderful true green color that occurs naturally, it is very popular among those who know about it.  It comes mainly in small sizes, so anything over 1ct goes at a premium, and only a tiny percentage of stones are over 2 ct.  The dark greens with a small percentage of blue are insanely expensive, the grassier greens are cheaper.  Tsavorite is tougher than emerald, and crisper in appearance.  I love this stone.

Now let’s get to the cutting.  Below is a picture of the piece of rough that D. selected.  This is a nice clean piece of a medium to dark forest green with an initial weight of 1.52 ct.  According to D., its initial shape suggests to make it an emerald cut, and since we didn’t have any particular plan for the piece, we went with what was best for the stone (and what would preserve the most weight).



The next picture is of the first cut, where D. pressed the stone against the cutting wheel from all sides with his finger, thus chopping off the edges and creating the basic emerald shape.  The rough went down to 1.31 ct in the process, which is a very small loss.  You can lose up to 80% of your rough in the cutting process.

So here’s a picture of stage two.



Before having to put it on a stick to cut the finer facets, D. was able to shape the rough down one more time.  This time, the stone went down to 1.06 ct.  Interestingly, that is what D. predicted.  His guess is that the stone will be about 1 ct when he’s done.  D. then polished one side of the stone with diamond powder so you can see that it will come out clean.  Here’s a picture.



And that’s where we are at this point.  The finer facets will take longer, and D. has some other cutting orders (8 emeralds for a special order), so I have to wait.  I hope to see the final product in a couple of weeks.  The stone could also break in the process, however.  But if it doesn’t, this is going to be a very fine gem. 

1 comment:

  1. This is so wonderful, thank you for posting! just found your blog today, going through the entries from the beginning :)

    ReplyDelete