Garnets: much more than a red gem

English: Collection of loose cut Garnet gemstones.
English: Collection of loose cut Garnet gemstones. (Photo credit: Wikipedia)

Continuing in the gemstones for fantasy writers series, let’s look at versatile garnets. If you aren’t too familiar with garnets, you may think of them as dark, sometimes brownish and relegated to Victorian jewelry but there’s much more to them.

As with tourmaline, garnet is a family of minerals with similar structure, in this case a silicate of the form X3Y2(SiO4)3, where X can be calcium, ferrous iron, magnesium, or manganese; and Y can be aluminum, ferric iron, chromium, manganese, silicon, titanium, zirconium or vanadium. Wikipedia lists 27 different minerals classified as garnet but only about 5 varieties are typically used as gemstones. Garnet is generally formed in heavily metamorphized rocks like schist as it takes a lot of heat and pressure.

English: Fragments of Rhodolite Garnet crystal...Garnet is quite common- I’ve found alamandine in gravel in the Adirondacks in New York and as to be expected with so many minerals in the family, it can be found all over the world. As a gemstone, it comes in almost as many colors as tourmaline, except for blue. However, it also doesn’t show tourmaline’s tendency for multiple colors in a single crystal. Crystals are “chunky” rather than long prisms and range from dodecahedrons to trapezohedron to a mix of the two. Garnet is a bit softer to a bit harder than quartz and is sometimes used as an abrasive.

Pyrope and almandine are the garnets that most readily come to mind. Bohemia provided much of the garnet used in Victorian jewelry. It was dark red, sometimes brownish. Very dark stones are sometimes lightened by being cut en cabochon with the back hollowed out. These days, these two varieties are commonly used for beads or for lower end jewelry except for rhodolite: this quite pretty pink to purplish garnet is mid-way between Pyrope (which is Mg3Al2(SiO4)3) and Almandine (which is Fe3Al2(siO4)3), that is, it is a solid solution of the two Magnesium and Iron varieties.

Tsavorite (Photo credit: Wikipedia)

One of the most popular varieties of garnet is marketed as tsavorite (or tsavolite in Europe), a green form of grossular garnet which has become very popular for its clarity and sometimes emerald-like color.

In the fantasy world, it is probably best to stick to red garnet, since that is what most people will think of. For instance, rather than use the green tsavorite, you  might just want to stick with emeralds (and I’d recommend staying away from the term tsavorite since that comes from an African place name and may seem to be a bit of an anachronism to some readers.)

Sutton Hoo - Anglo-Saxon slider
Sutton Hoo – Anglo-Saxon slider (Photo credit: Kotomicreations)

But within the realm of red, garnet make can make for an interesting stone to sprinkle in native rocks- say the walls of a dungeon. For idols, it could provide a deep, red stone if you didn’t want to go with something as valuable as ruby. Similarly, for jewelry it might be suitable for lower nobility or merchants. As a reasonably cheap stone, it could also serve for warrior’s gear (where it would not break the bank if damaged). In fact, one of the most striking use of garnets was in Anglo-Saxon jewelry where it was cut as slivers used for in-lay, such as some of the spectacular Sutton Hoo pieces. Glass enamel has also been used for a similar effect.

Like most gemstones, synthetic material is available, with some variants not found in nature such as YAG used in lasers. Perhaps in a science fiction setting, you could extrapolate still more exotic garnets.


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