Rock Identifier
Polished bloodstone (heliotrope), likely (Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions) — mineral
mineral

Polished bloodstone (heliotrope), likely

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; dark green to gray-green, opaque to translucent, with red-brown hematite/jasper spots. Waxy to vitreous luster, cryptocrystalline structure, and no visible cleavage; specific gravity about 2.6.

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Physical properties

Mohs hardness 6.5–7; dark green to gray-green, opaque to translucent, with red-brown hematite/jasper spots. Waxy to vitreous luster, cryptocrystalline structure, and no visible cleavage; specific gravity about 2.6.

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron oxides producing the red inclusions; commonly associated with volcanic rocks. Most material is geologically young relative to host rocks, often Cenozoic or older hydrothermal deposits.

Uses & applications

Used as a lapidary stone for cabochons, beads, carvings, and tumbled specimens; historically used for seals and ornamental objects. It has modest jewelry and collector demand.

Geological facts

Bloodstone is also called heliotrope; the red spots are not blood but iron oxides, chiefly hematite or jasper. The pictured specimen may also be green jasper or epidote-bearing chalcedony, which can look similar.

Field identification & locations

Identify by its green chalcedony body, scattered red spots, glassy/waxy polish, and hardness sufficient to scratch ordinary glass. Common sources include India, Madagascar, Brazil, Australia, and Scotland; a streak or acid test can help distinguish look-alikes.