Bloodstone
Chalcedony (quartz)JewelryWiki Editorial·2 sources·Reviewed 2026-08-04
Dark green chalcedony flecked with red — traditionally the March birthstone before aquamarine largely displaced it. The red spots are iron oxide, not the "blood" of the legend, and the stone is also sold as heliotrope.
Properties
| Property | Value | Authority |
|---|---|---|
| Mohs hardness | 7 [1] | — |
| Specific gravity | 2.55–2.91 [1] | — |
| Chemical formula | SiO2 Read from the species entry, Quartz. IGS gives one hardness and density for chalcedony and names bloodstone among the varieties it covers. [2] | — |
| Crystal system | Hexagonal (trigonal), microcrystalline [1] | — |
| Common treatments | Dyeing, per IGS’s list of chalcedony treatments. [1] | — |
| Care cautions | Durable for everyday wear. If dyed, keep from solvents and strong sunlight. [1] | — |
Sources
- International Gem Society — gemstone articles — International Gem Society (IGS, gemstone information articles (gemsociety.org))
- Handbook of Mineralogy — Mineral Data Publishing / Mineralogical Society of America (Handbook of Mineralogy, Mineral Data Publishing)