Plasma

Description

(geology) An archaic name for a translucent green gemstone. Plasma stones are composed of a bright green cryptocrystalline quartz (chalcedony) and often have patches of white or yellow. They are native to India and Egypt. Many poor quality emeralds have been misidentified as plasma gemstones. Plasma stones are called bloodstone when they contain small red spots of jasper.

Synonyms and Related Terms

chalcedony

Physical and Chemical Properties

• Fracture = conchoidal.
• Luster = waxy.
• Streak = white.
• Mohs Hardness = 7.0
• Density = 2.6 g/ml

Resources and Citations

• J. Ogden, Jewelry of the Ancient World, Rizzoli International Publications, New York, 1982.
• Mineralogy Database: Quartz