Definition of dioptase
: a mineral CuSiO2(OH)2 consisting of hydrous copper silicate and occurring in emerald-green crystals and massive (hardness 5, specific gravity 3.47)
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Origin and Etymology of dioptase
French, probably from Late Greek dioptos transparent (from Greek dia- + optos visible, from opsesthai to be going to see) + French -ase (as in euclase) — more at optic
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