Garnet: It Gets No Respect

by Richard O. Martin

2,74 arch malaia

mali 1.63 arch

When January arrives I automatically think of two things: Tucson and garnets. I also reflect that in the gemstone world garnet, the January birthstone, is a lot like late comedian Rodney Dangerfield: it gets no respect. Gem expert Joel Arem calls garnet “…perhaps the most underrated of all gems.”

Yet for at least 5,000 years garnet was one of the most favored of all human possessions. The earliest known use of garnet in jewelry dates from 3200 B.C. in a diadem found at Abydos, Egypt. Garnets were featured in the Biblical breastplate of Aaron and in ancient societies noblemen treasured their yellow “Lyncurium Stones” and mysterious deep red “carbuncles.” At night they held carbuncles up to the firelight and peered through them to discern mystic and magical revelations in the dramatic kaleidoscope of red, purple and rose “fires” thus revealed.

Greek and Roman noblemen used garnet intaglios in seal stones and rings. Garnets were prized among the state jewels in many kingdoms. Royal Saxon garnet cloissone of the highest order of beauty and craftsmanship is on display in the British Museum’s Sutton Hoo collection. The finest red garnets were long valued as greatly as ruby.

What happened to undermine the high public esteem garnet had enjoyed for so long?

About a hundred years ago, during the reign of England’s Queen Victoria, the market was flooded with cheap, unattractive machine-made jewelry set with dark brownish-red pyrope garnets from Bohemia. The vast amount of this cheap jewelry and the low quality of its workmanship and stones have tarnished garnet’s image to this very day. The word “garnet” has sadly become synonymous with “cheap,” and despite the amazing color variety in this large gem family – every color, including blue! – the vast majority of jewelry consumers thinks garnet is always red.

This has led to a situation in which a few exceptional garnet colors are well known and prized, but their beautiful relatives are often tossed aside by some jewelers and gemologists as “just garnet, darn it!” Fine green grossular garnets are marketed as Tsavorite and seldom as “garnet”. The same is true of chrome green Russian demantoid (the green hue of yellowish andradite garnet, a spectacular gem in its own right throwing dispersion colors more strongly than diamond.)

Because of these backward marketing attitudes among some of the very people who should know better, most garnet today excites the general public about as much as pocket protectors, watch fobs and floor wax.

I think that’s wrong and shortsighted. Those of us in the hobby/business of gem cutting can do a lot to change public perceptions about one of the wonders of the gem world. With rising demand for colored stones it seems strange that many jewelers have failed to inform themselves about garnets and to seriously promote the beauty of this wide-ranging gem family.

I’ve been thinking a lot about what makes garnet a candidate for the respect it should have. Here is a list of some of garnet’s virtues.

royal 10 x 8 arch

Garnet occurs in every primary color and most intermediate shades. “Hold the phone!” some of you are muttering. “Garnet doesn’t occur in blue!” That’s no longer true. I’ve seen blue garnets with my own eyes. Some color-change garnets from new locations around the world shift from blue to shades of pink and red and other colors, too, depending on the lighting. Some of them are blue all the time. So the old mantra about “every color but blue” needs to be revised. Lately I’ve heard rumors -- nothing I can confirm yet -- of the discovery of an indicolite blue/green garnet. (A garnet of this color was reported in 1968 in Lesotho and named Knorringite, but it has not been available in quantity).

At 6.5 to 7.5 on the Mohs scale, depending on the species, garnet has adequate hardness for gem use. Consider the popularity of stones of equal or lesser hardness like neon apatite, tanzanite, fire opal, turquoise, kunzite, iolite, precious opal, lapis lazuli, moonstone, peridot, tourmaline, scapolite and very soft organic gems like pearl, coral and amber.

tril 1.73

Refractive Index
The light-bending abilities of almandite and spessartite are higher than corundum and most other popular colored gems except zircon. Andradite gets right up there and rubs shoulders with zircon at 1.875 to 1.89! Grossular, pyrope and intermediate mixed-species garnets like “rhodolite” and “malaya” check in with RI’s in the higher third of the scale. The dark colors of some garnets offset this RI advantage by dampening their brilliance, but in general cutters can expect to create unusually bright gems from medium to lightly color saturated garnets. And they are available, with new sources coming on-line even as I write.

Tsavorite and so-called “Mint Grossular” are sparkling green examples of the “RI factor,” but faceters who have not cut other grossular garnets like hessonite or some of the lovely (and largely ignored) lighter pale orange or yellow to near-colorless shades are missing a treat.

The brilliance and higher-than-diamond dispersion of the andradite/demantoid garnet species is a surprise to many jewelers. Most garnets in the pink-to-red colors have very appealing brilliance when properly cut. The amazing sparkle of light-toned spessartite has recently found acceptance by jewelers due to new discoveries of this beautiful orange to “aurora rose”-colored gem in Tanzania, Nigeria, Madagascar and Afghanistan. An especially beautiful “orange crush” color of spessartite, called Mandarin and several other trade names is mined sporadically in Namibia.

Garnet crystallizes in the cubic system, making it singly refractive like diamond and spinel. Big deal, you may say. Well, it is a big deal to cutters trying to orient rough for the best yield and color. Dichroism and trichroism in gems like tourmaline, corundum, tanzanite, iolite and others can cause big headaches for cutters. The best color always seems to be in the direction of lowest weight yield. While garnet can exhibit some problems in orientation due to its occasional flattish tabular shape and characteristic rutile inclusions, pleochroism presents no problems. And there’s no double-refractive fuzzing of the pavilion facets when viewed through the table as with zircon, peridot and a few others. Garnets can look “sleepy” because of included “silk” and “sugar” but not because of double refraction.

cc garnet 1.66 ct

No Synthetics or Treatments
There are no laboratory-made garnet synthetics currently on the market to my knowledge. Few garnets other than Tsavorite currently have values high enough to make synthesizing them profitable. That will change if garnet increases in popularity and price as I think it will. There are man-made “garnets” like Yttrium Aluminum Garnet (YAG) and Gallium Gadolinium Garnet (GGG) but these stones don’t duplicate any garnets so far found in nature and aren’t even silicates like true garnets. They are called “garnets” because their cubic internal atomic structures resemble the garnet group.

So far as I can learn, there are as yet no widespread processes (heating, irradiation, etc.) to “treat” garnet to improve color or clarity except for heat treatment of demantoid to permanently improve color. This is not to say it isn’t possible or even taking place, but I haven’t been able to find evidence of treatment at this time with one exception. There is an oddity called “Proteus that was briefly marketed as “the first and only garnet treatment ever announced.” This Idaho garnet displays a metallic luster on its surface resembling marcasite, while still allowing light to pass through to show deep red reflections from the interior. According to the marketers of Proteus, the color centers of certain types of garnets can be reorganized and a metallic component of the garnet itself is driven to the surface, “plating” it. While I haven’t yet seen these stones, this treatment doesn’t strike me as anything I want to rush out and buy except as an historical novelty. One thing’s for sure: these stones should be easy to identify!

There are several kinds of truly attractive garnets on the current market at reasonable prices, taking into account the scarcity and value of desirable gem materials generally. If chosen carefully, garnet offers beginning and veteran cutters and those on a budget the chance to work with fine natural gem material at an affordable price.

single of 1.25 pair

Increasing Value
I remember going to Tucson in the early 1980s and seeing huge top-color Tanzanian rhodolites bagged up like purple grapes in a supermarket for sale at very low prices by today’s standards for that size and quality. The cover of the February, 1980 “Lapidary Journal” featured an incredible 49.62 ct. bright orange malaia/malaya garnet. In fact, intense pure orange or orange-pink colors at that time were the hallmarks of fine malaia, and quite a bit of that material was available. How long has it been since we’ve seen rough in those sizes and colors, and what would it be worth today?

It’s only my opinion but I think there are some greatly undervalued garnets in the present market, especially some of the intermediate pyrope-almandine colors that are often (incorrectly) gathered together under the one-name-fits-all term “rhodolite.” Any red-toned garnet that doesn’t also show purple or violet is not rhodolite…but that’s a tale for another time. Another garnet type I feel is very far undervalued is the highly brilliant and dispersive Mali garnets that range from grossular into andradite. These are often described as “grandite” garnets but many should be designated as grossular.

Previously unknown or undescribed garnet colors are now being found regularly in what I call the “great garnet incubator” of east Africa including Madagascar. Due to garnet’s propensity to “mix and match” two or more species in various proportions, delightful hues are often found that cut into superb gemstones. The sharp-eyed garnet buyer can occasionally find such stones at bargain prices due to ignorance on the part of the seller.

Greater Public Acceptance
Over the past 15 or 20 years public tastes in colored gems have begun to change. Many trade groups, cutters and designers have helped preach the “gospel” of quality cuts showing off the many exciting colors of stones available. The old “diamonds-only” attitude of some traditional jewelers, who debased the value of colored stones by restricting their sales to “birthstones,” is beginning to change dramatically. The public is now looking for more choices. Maybe the time for fine garnets has come again.

There are many other good things to be said about the garnet group, but that’s enough for this session. There are also a few things on the downside that should be mentioned. But those are topics for later articles.

1.54 med. brand ov

malaia 4.5 arch

Copyright © 2005 by Richard O. Martin

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