Dioptase with Calcite Gemstone Carvings The very first stone tools

The very first stone tools were not created by humans

Crystalline Gold is purchased not for its spot market value but for its rarity

spindle-shaped fossils have surfaces marked by weak spiral lines in a helix

Quartz occurs in crystalline masses

Although most hair remains are orange in color

Dioptase with Calcite Gemstone Carvings The very first stone toolsDioptase 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).