The name of this gem derived from Greek "????????" that means, verbatim, "easily frangibility."
Euclase first appeared in Europe in 1785. The merchants brought this gem from South America (probably Peru or Brazil). However, some sources tell us that Russia is a real birthplace of this gemstone. The abundant deposits of Euclase located in the Ural Mountains, in the vicinity of Orenburg. One unknown traveler furnished this stone in Europe.
The mines of Euclase are solely in two locations. One of them is the gold placers of the Sanarka River in Russia. The second location is Boa Vista, the province of Minas Geraes. It's a region in Brazil, where Euclase is mined along with yellow Topaz, however, in small quantity. Some crystals of inferior quality and insufficient value came to the market from the Alps. But they are not suitable neither for jewelry purposes nor collections. Russian specimens frequently occur of an inferior size compared to their Brazilian rival. But some samples exceed three inches in length.
Properties of Euclase
Euclase is a pretty hard stone similar in hardness to Beryl (7,5/10, according to the Mohs Scale). But this quality is not enough to get into the list of genuine precious stones. It is somewhat transparent and suitable for a good polish. However, as we know from its name, Euclase is not appropriate for cutting due to its frangibility. In spite of this, there is a variety of jewelry made of Euclase on the market. Because of its extreme rarity, each consumer, who purchased Euclase jewelry at an affordable price could become an owner of very exclusive jewelry.
Euclase possesses double refraction, distinct pleochroism, and specific gravity equal to 3,05-3,1. These qualities could be useful to distinguish this gemstone from blue Topaz and any Beryl, including Aquamarine. Moreover, we may, in additional, separate it from Beryl, thanks to the existence of water in its composition. This gem easily electrified by friction and it resists acid, furthermore. Cut Euclase possesses hyaline luster and quite cute brilliance. Its color ranges from colorless to sea-green and bluish tints. Externally, the crystals of Euclase are sparkle.
Thanks for Euclase crystal image to Géry Parent