There are six different kinds or species of January’s birthstone, the garnet, each stunningly lovely in its own right. Here’s a list of all six, along with a bit of info about each and pictures of them in their rough forms.
(1) almandine – most common form of garnet; deep red to reddish orange, purple red to red purple, usually dark, transparent; found in metamorphic rock, like mica schists; also called “carbuncle”; ground up and used as an abrasive; sometimes confused with pyrope, but most almandine is much more opaque; found in Sri Lanka, Myanmar, Australia, Switzerland, East Africa, and the US
(2) pyrope – the only garnet species that’s always red, and the red can be so dark it looks black or purple; can be confused with almandine, but has fewer flaws and inclusions; found in Bohemia, Czech Republic, Switzerland, Scotland, Tanzania, Kenya, Canada, and the US
(3) grossular – light to dark green, light to dark yellow to reddish brown, occasionally translucent to opaque pink, rarely colorless; some examples of grossular garnets are Hessonite or cinnamon stone; also tsavorite, a rare green grossular garnet found in India; grossular garnets are also found in Tanzania, Sibera, Sri Lanka, Brazil, and the US
(4) uvarovite – emerald green; the rarest of the garnet species, and seldom found in crystals large enough to be faceted, because the mineral that causes the lovely green color also stunts crystal growth, so it’s usually seen as drusy in jewelry; found in Canada, Spain, Finland, Norway, South Africa, and Russia
(5) spessartine – bright orange, orange-red, yellow to red; also known as spessartite; named for the area of Bavaria, Germany, where it was discovered in the 1990s; second rarest garnet; also found in Brazil, Madagascar, Australia, Myanmar, India, Afghanistan, Israel, Tanzania, the US and Bulgaria
(6) andradite – most commonly golden to brown; much less commonly found in a green form known as demantoid, an orange-yellow form known as topazolite, and a black opaque form known as melanite; found in Norway, Brazil, Italy, Russia, Ukraine, and the US