Jasper

Jasper (mineral), opaque, cryptocrystalline variety of quartz. The mineral takes a high polish and is used as a gemstone. It is usually stained by impurities and occurs in various colors, such as red, green, yellow, and blue. When the colors are arranged in bands, the mineral is called riband jasper; a variety containing alternating bands of red and green is known as Siberian jasper. Mottled yellow or brown varieties of jasper are called Egyptian jasper. Agate jasper is intermediate in structure between true jasper and chalcedony. Inclusions of red jasper occur in heliotrope.

The jasper mentioned in the Bible as one of the stones in the breastplate of the high priest and as the foundation of the wall of the New Jerusalem is believed to have been a dark green, opalescent stone. The jasper of the ancients was a partially translucent stone, probably containing some chalcedony and a variety of the latter known as chrysoprase.