sedimentary
Bloodstone (Heliotrope)
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
Hardness: 6.5-7 (Mohs scale), Color: Dark green with red speckles, Luster: Vitreous to waxy, Crystal Structure: Trigonal (Cryptocrystalline), Cleavage: None, SG: 2.58-2.64
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Dark green with red speckles, Luster: Vitreous to waxy, Crystal Structure: Trigonal (Cryptocrystalline), Cleavage: None, SG: 2.58-2.64
Formation & geological history
Bloodstone is a variety of chalcedony formed through the precipitation of silica in cavities of sedimentary or volcanic rocks. The green color is caused by chlorite or hornblende, while the red spots are inclusions of iron oxide (hematite).
Uses & applications
Primarily used in jewelry for cabochons, beads, and signet rings. It is also a popular collector's mineral and is historical used as a March birthstone.
Geological facts
In the Middle Ages, the red spots were believed to be the blood of Christ. It was historically called Heliotrope, meaning 'sun turner' in Greek, because it was once believed that it could turn the sun red when placed in water.
Field identification & locations
Identify in the field by its distinctive forest-green waxy body and pinpoint red inclusions. It is commonly found in India, Brazil, Australia, and parts of the United States like California.
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