Garnets, to me, are some of the most “disorganized” gems
available on the market today. Their
sheer variety, but also their names, can be very confusing to the uninitiated,
leaving the connoisseur not far behind.
Here’s an attempt to cut through the confusion.
“Garnet” really refers to a variety of gemstones that are
related but not identical in their chemical properties. In terms of their chemical “species” (if that’s
a good name for it), there are Andradite, Almandine, Grossularite, Pyrope,
Spessartite, and a couple of others.
Different websites (and books) group the chemical varieties together in
different ways. I.e. Sometimes
Grossularite is listed under Andradite, sometimes they’re separate. Many garnets are actually mixtures of these different
chemical compounds (meaning the molecular structure is not exactly one or the
other), so what goes with what seems to be more of a matter of how you like to
group (and market) your gems. So let’s
sort them by using the names you would most commonly encounter when the gems
are marketed to you (in a store, on a website, etc.):
1.
Red: yep, just “red”, I don’t know another name. Those are usually a mix between pyrope and
almandine, or either. The “Ant Hill”
variety is found only in Arizona. It’s a
pretty variety that’s a little more bright red, but like all red garnets, it
can appear sooty in evening light and has to be cut well so it’s not
blackish. Any red garnet is easily
available on the market and very inexpensive.
The lowest wholesale price I’ve seen is about $1 per carat.
2.
Rhodolite: also a mix between pyrope and
almandine, it’s less common, especially in larger sizes (over 10mm). Rhodolites are any form of pinkish and
purplish garnet, and sometimes appear under names such as “cranberry”,
“raspberry”, or “rose”, depending on the whim of the gemdealer who sells them. Rhodolites come from just about anywhere in
the world, with Tanzania producing some of the nicest ones. It’s also readily available in smaller sizes
but carat prices are more like $10, wholsale, sometimes more (and on occasion
less).
3.
Spessartite: chemically it falls under
Andradite, but the name comes from the Spessart forest in Germany, where it was
first found. Nowadays spessartite comes
mainly from Tanzania and Nigeria. It is
a brownish orange, with the cleanest and brightest, most orange stones usually
termed “Mandarin” garnet. Spessartite,
especially larger pieces, can be quite expensive, and it is almost never as
clean as rhodolite and the reds, both of which should be totally without
inclusions. Prices are anywhere from $20
per carat for tiny sizes to $1000 per carat for huge chunks. Or more.
4.
Tsavorite: a grossular subvariety, which also
falls under andradite, tsavorite ranges from yellowish green (which is less
expensive) to a dark rich almost emerald green with secondary hues of
blue. It is named after Tsavo national
park in Kenya, but the mine is on the border to Tanzania, so the latter mines
Tsavorite as well. Gems over 3 carats
are extremely rare, and in recent years Tsavorite production has decreased
drastically, so you are going to see an increase in price. Last year I was getting small stuff starting
at $40 per carat, that price is long gone.
Large pieces are a few hundred per carat to a few thousand.
Tsavorite, Merelani Mint and Color Change Imperial Gernet |
5.
Merelani mint: also a grossular garnet, and
really a light colored Tsavorite without any secondary yellow, Merelani’s are
named after the Merelani mine in Tanzania, the only place in the world where
they are found. Production is extremely
small for this reason, and as of late I’ve hardly seen them on the market at
all. Prices have skyrocketed accordingly,
whereas a year or two ago, nobody cared about this minty color. Prices are all over the place, and since they’re
nearly unavailable, it’s hard for me to say anything concrete.
6.
Demantoid: the most famous of the greens, it’s
another andradite garnet. It is a very
clean stone with a high refractive index, and usually has an olive color
(though more apple green ones have been noted for their extraordinary
beauty). It traditionally came from
Russia, but now it is also mined in Africa.
Demantoid is very scarce. Price
per carat: if you pay $100 for tiny sizes, you are lucky.
African Demantoid Garnet |
Mali Garnets |
. 8. Umba or umbalite garnet: a red or reddish pink
garnet named after the Umba valley in Tanzania, where you also find the Umba
sapphires. It’s not too expensive yet,
it’s basically a fine quality rhodolite garnet.
But I’ve also seen it cost 2-3 times as much, depending on cut.
9.
Malaia garnet: the name (I looked this up) is
Bantu, and the name is usually reserved for any light pinkish, peachy and peachy
orange color garnet (sometimes also orange, which makes it confusing because
spessartite is also orange), mostly of African origin. It is mined in Tanzania and Madagascar at
present. Malaia garnet can have various
chemical compositions, so I’ve not seen it classified except in a thread on
Pricescope, where it was deemed as a mixture between pyrope and Spessartite. Some Malaia garnet can be expensive, but I
think that’s just hype. The pricing
should be more or less like Mali garnet, except for larger stones. I’d personally say the rosy and peachy colors
(imperical colors, or padparadscha colors) are the most unique and
interesting. I’m not sure about
prices. I’d say somewhere between Mali
and Spessartite but it really depends on the piece and on the seller.
10.
Hessonite: this garnet is also orange brown like
Spessartite, but usually not as bright.
It belongs with the grossular family and is neither particularly
beautiful nor expensive. Lately I
haven’t seen it marketed much though. So
perhaps other names for the variety have superseded it. Small sizes are cheap, like red garnet.
11.
Color change garnet: first of all, color change
is observed in almost any variety of garnet: red, orange, pink, green, and
blue. In other words, some rhodolite,
some malaia, some umbalites and some pyropes all change color (but tsavorite,
spessartite, and demantoid don’t). If
you have a nice garnet of this variety, try looking at it under different
lighting conditions, perhaps you see a change that you never noticed
before. The most expensive color
changing variety, by far, comes from Tanzania and Madagascar, and it is blue,
blueish green, or green in color (though dark green, not like Tsavorite), with
changes usually from the blue or blueish green varieties to purplish and
pinkish tones, whereas the green ones change to red. I’ve only seen a red-green changer once,
though. It was cool. Many of the blue and dark green color changers
are dark in color, especially the larger sizes, and they can have grey
mask. Over 1 carat, they are nonetheless
very expensive (think Tsavorite for comparison). But they are largely very clean stones, and
when you have a bright blue one, you have a real winner! Prices can be $100 starting if you are lucky,
but anything over a carat is more like a few hundred. Anything over 2 carats is very rare.
Tanzanian Color Change Garnet 1+ Carat, Blue and White Light |
Gemstone availability changes constantly, keep that in mind
when you collect. A simple rule is that
larger stones are rarer than small ones, and that you want as clean as stone as
you can get for the variety you are looking at.
Great post!
ReplyDeleteI love this post, it's one of the most informative I've read about garnets. And also maybe bc 2 of these pictured garnets have come to live with me, and I expect to add a third (the tsav!), lol.
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