Jasper

Jasper, an aggregate of microgranular quartz and/or chalcedony and other mineral phases, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron(III) inclusions. The mineral aggregate breaks with a smooth surface and is used for ornamentation or as a gemstone. It can be highly polished and is used for items such as vases, seals, and snuff boxes. The specific gravity of jasper is typically 2.5 to 2.9. A green variety with red spots, known as heliotrope (bloodstone), is one of the traditional birthstones for March. Jaspilite is a banded iron formation rock that often has distinctive bands of jasper. 2Etymology and history The name means "spotted or speckled stone", and is derived via Old French jaspre (variant of Anglo-Norman jaspe) and Latin iaspidem (nom. iaspis) from Greek ἴασπις iaspis (feminine noun), from an Afroasiatic language (cf. Hebrew ישפה yashpeh, Akkadian yashupu).Green jasper was used to make bow drills in Mehrgarh between 4th and 5th millennium BC. Jasper is known to have been a favorite gem in the ancient world; its name can be traced back in Arabic, Azerbaijani, Persian, Hebrew, Assyrian, Greek and Lati