Jasper 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
Heliotrope (mineral) to several magical properties, which were attributed to it from Late Antiquity. Pliny the Elder (1st century) mentioned first that the magicians used it as a stone of invisibility. Damigeron (4th century) wrote about its property to make rain, solar eclipse and its special virtue in divination and preserving health and youth. Heliotrope features as an invisibility stone in one of Boccaccio's stories in the "Decameron" and as a healing magic item in a musical comedy derived from it. Heliotrope is sometimes used in carved signet rings and is the traditional birthstone for March. The primary source of the stone