• Webster's Revised Unabridged Dictionary
    • n Euclase (Min) A brittle gem occurring in light green, transparent crystals, affording a brilliant clinodiagonal cleavage. It is a silicate of alumina and glucina.
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Century Dictionary and Cyclopedia
    • n euclase A very brittle mineral of a pale-green color and high luster, crystallizing in prismatic crystals belonging to the monoclinic system. It consists of silica, aluminium, and glucinum, and occurs in the topaz districts of Brazil and the gold districts of the southern Ural, and sparingly in the Alps.
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Chambers's Twentieth Century Dictionary
    • n Euclase ū′klās a silicate of aluminium and glucinum occurring in pale-green transparent crystals.
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Webster's Revised Unabridged Dictionary
Gr. e'y^ well, easily + to break. Cf. F. euclase, G. euklas,. See named from its brittleness
Chambers's Twentieth Century Dictionary
Fr.,—Gr. eu, well, klasis, breaking.


In literature:

Euclase occurs with topaz at Boa Vista, near Ouro Preto (Villa Rica) in the province of Minas Geraes, Brazil.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 8" by Various