Garnet is a striking stone, red as blood and ruby’s second most infamous imitator (the first being spinel). Garnet holds a few prestigious roles in the world. It is the state gemstone of New York. New York is also home to the world’s largest garnet mine in the world, the Barton Mines, in the Adirondack Mountains. It enjoys significance in the industry for its coveted abrasive properties, which are superior to sand or most powdered rocks. Garnet is also a significant geological indicator of diamonds. This is because rock (specifically xenoliths, rock trapped in rock) deep in the mantle is lifted through pipes by volcanic eruptions. These pipes contain a high quantity of garnets, but also some diamonds. The garnets that are lifted this way are very different from the common shallow garnets found in the crust.
A comprehensive history of garnet is too much for the scope of this article, but a summary of its relation to the birthstone is doable.
According to Kunz’s landmark history of the birthstones, virtually every major culture agreed that January’s stone is garnet. The few who did not are in the minority. Sometimes, garnet would share its place with another stone. More often than not, it was jacinth, a variety of zircon set in the breastplate of the High Priest of Israel.
There is not much more to garnet’s history as a birthstone; it really is this simple. As far as the author is concerned, there have not been any major challenges to garnet’s position as January’s birthstone either. To this day, the GIA list does not name any other stone for January’s birthstone.
Garnet is not actually by itself a mineral. For the purpose of the article, however, they are collectively called “garnet.”
Garnet is really several types of minerals. Only a handful have any relevance, however, and they are pyrope almandine, spessartine, grossular, and andradite.
If you’ve seen a blood-red garnet, it was probably a pyrope, meaning “fire eye.” Pyrope is also known by dozens of misnomers. To make matters more complicated, many describe it as a “ruby” which could not be further from the truth!
Here are just some of the (incorrect) names for the pyrope garnet: American ruby, Arizona spinel, Cape ruby, California ruby, Colorado ruby, Ellie ruby, false hyacinth, Fashoda garnet, gooseberry stone, oriental garnet, Uralian emerald, Bohemian diamond, Montana ruby, and cinnamon stone.
According to Frank B. Wade, garnet sellers would not call their pieces garnet intentionally. He claimed that the reason for this was due to how bad garnet was as a gemstone compared to every other piece. If true, this explains why many continued to be called ruby despite being known as garnet. “Cape ruby” does sound more romantic than “garnet” in any case. .
There is some evidence to suggest Wade’s claims are correct. But there is also evidence of a more sinister purpose. An Australian article on fake gemstones in 1929 reads, “There is another garnet called ‘Cape Ruby,’ which is sufficiently like a real ruby to deceive the unwary.”
“Faking Jewels. 'Cultured Pearls' Are Only Half-Fakes." The Port Macquarie News, 20 Apr 1929, P.8
Kunz, George Frederick. The Curious Lore of Precious Stones. Lippincott, 1913.
Schaller, W.T. "Gems and Precious Stones." Title of Collection, edited by Editor's Name(s), Publisher, Year, Page range of entry..
Wade, Frank B. “Garnet – The January Birth Stone.” The Jewelers' Circular. United States, Jewelers' Circular Company, 16 Jan. 1917. P. 43