Although many associate the January birthstone, garnet, with the color red, these gems can come in many other colors, including yellow, orange, green, and even blue.
Garnets are beautiful gemstones. The name comes from the Latin word for seed, most likely a reference to a pomegranate seed. They come in a variety of colors because garnets actually belong to a group of minerals. There are many different garnet species, each with a similar but distinct chemical composition.
Garnets are famous for their range of rich hues and tones. This makes color the most important factor when evaluating the quality and cost of garnets. Typically, red garnets are the most common and affordable option. Rare green garnets, on the other hand, will come with a much higher price tag. Red garnets are also evaluated based on their tone, which means their relative lightness or darkness. A lighter, more saturated or “intense” red stone will command a higher price than a darker stone.
Green garnets that come close to a rich emerald-green will generally cost more than yellowish or lighter greens. Greens with medium tones will also typically cost more than those with very light or very dark tones.
Almandine: The most common garnet gemstone, almandine can come in many colors. However, the almandine-pyrope blend creates the deep red color popularly associated with garnets. Rhodolites are a purplish red almandine-pyrope mix with some spessartite. The more spessartite they contain, the lighter their color.
Andradite: One of the rarest and most prized garnet types, andradite has the highest dispersion or “fire” of all garnets. That means it breaks up light and reflects it back in sparkling points of multiple colors. Andradite even has more fire than diamond. Andradites come in a wide range of colors, including green, yellow, brownish red, and black. Demantoid, the green variety of andradite, is the most valuable garnet and one of the rarest gems in the world.
Grossular: Grossular garnets come in nearly every color of the rainbow. However, unlike most garnet varieties, they rarely have red or dark colors. Gem connoisseurs love them for their light to medium tones. They make wonderful jewelry stones. Light, minty green grossulars are particularly popular. “Cinnamon-colored” hessonites and emerald-green tsavorites are also highly prized varieties. Mali garnets combine grossular and andradite chemistry and can show green, yellow, or brown colors. If they have light colors, properly faceted Mali garnets can show exceptional brilliance or “brightness.”
Pyrope: When mixed with other types of garnet, pyrope can create the classic red garnet hue. Chrome pyropes are especially popular for their deep red color and can rival rubies. Collectors refer to them as “anthill garnets” because ants in Arizona have been known to find these stones underground and carry them to the surface.
Spessartite: Somewhat rare, spessartites can display a range of orange colors. Mandarin garnets, a spessartite variety with a vibrant orange color, are highly prized. Malaia garnets can have pinkish, reddish, or yellowish orange colors. These gems are a complex blend of many garnet species, usually with a large percentage of spessartite.
Uvarovite: The rarest member of the garnet family, uvarovites show a beautiful, rich, dark green color. However, they usually don’t have the size or transparency to be cut into jewelry stones. Jewelers sometimes use uvarovites in their creations as druzy, a layer of tiny, uncut natural crystals.
Of the complex family of garnets only two species are reported to exist in B.C., Almandite and Andradite. Perfect, clear-red almandite crystals up to 3cm. in diameter occur in mica schist along the Stikine River. Andradite garnet in fair crystals, but not suitable for cutting is found on Texada Island. In a recent study, 16 garnet occurrences in 7 large areas were recorded; Southern Shuswap-Nelson area, Shuswap Lake-Vernon-Okanagan area, Revelstoke-Frenchman Camp-Big Bend area, Canoe River-Valemount-Mica Creek area, Aiken Lake-Mesilinka River area, Hope-Yale-Harrison Lake-Lytton area, and Prince Rupert-Skeena River-Douglas Channel area. Most of this garnet is high-quality commercial grade, suitable for lapping and grinding with minor amounts useful for cutting.