Dioptase/ChrysocollaDioptase crystals are emerald green and translucent. The mineral got its name from the Greek words for "to see" and "through" because of the ability to see internal cleavage planes of the small crystals. The mineral forms in rhombohedral crystals (usually less than 1cm in size) with a chemical composition of CuSiO3 (H2O). Theophrastus, the successor to Aristotle in ancient Greece was the first to use the Greek word Crysos " meaning gold" and kolla "