Euclase Gemstone

Name | Brief HistoryMiningProperties

Euclase is a collectible gemstone of sea-blue color, it its quite rare and, therefore, is not often used in jewelry, however, it possesses all the virtues of precious stone and is suitable for jewelry purposes, nonetheless it is classified as semi-precious stone.


Euclase acquired its name, thanks to the term “easy cleavage,” that is pronounced in Greek as “εὖκλασις” and means, verbatim, “easily frangibility,” thanks to the verb “klaso.”

Brief History

Euclase Gemstone

Euclase first appeared in Europe in 1785, and was delivered from South America (probably Peru or Brazil), however, some sources tell us, that it, indeed, was brought from Russia (where has been obtained in the Ural Mountains in the vicinity of Orenburg), by one unknown traveller.


Euclase is mined solely in two locations: one of them is the gold placers of the Sanarka River in Russia (Ural mountains) in the vicinity of Orenburg, where it, probably, was obtained first; the second location is Boa Vista, the province of Minas Geraes, a region in Brazil, where Euclase is mined along with yellow Topaz, however in small quantity. Some crystals of very small size, were also found in the Alps, however, those specimens have not been useful neither for collection nor for jewelry purposes.

Russian specimens frequently occur of a good size, compared to Brazilian, however, seldom exceed 3 inches in length.

Properties of Euclase

Euclase is pretty hard stone, same as Beryl, but the hardness of 7,5/10 (according to the Mohs scale) is not enough to be considered a precious stone. It is fairly transparent and suitable for a good polish, however, as we know from its name, Euclase is not appropriate for cutting, due to its frangibility. But, nevertheless, there is a variety of Euclase jewelry on the market.

Thanks to its extreme rarity, each consumer, who purchased Euclase jewelry at an affordable price could become a wearer of very exclusive jewelry.

Euclase possesses double refraction, distinct pleochroism, and specific gravity equal to 3,05-3,1,– the qualities, which could be useful to distinguish this gemstone from blue Topaz and any Beryl, including Aquamarine. Moreover, it could be, in additional, distinguished from Beryl, thanks to the existence of water in its composition. It could be easily electrified by friction and it is not attacked by acid, furthermore.

Cut Euclase possesses hyaline luster and quite pretty brilliance, its color ranges from colorless to sea-green and bluish tints; externally the crystals of Euclase are splendent.

Tanks to Euclase crystal image to: Géry Parent

June 23, 2018

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