Bloodstone
Last updated: April 2026
Dark green opaque chalcedony with distinctive red, orange, or yellow spots from iron oxide inclusions (hematite, goethite). The green-with-red-spots pattern is visually diagnostic and rarely confused. Primary modern source is India; also Australia, Brazil, and China. Color is natural; treatments are rare. Sometimes sold as jasper in trade — jasper is fully opaque chalcedony with high impurity content.
Bloodstone has a specific gravity of 2.61 and a refractive index of 1.530–1.543, with a Mohs hardness of 6.5–7.0. It is aggregate.
Physical & Optical Properties
Measured with a polariscope, a refractometer, a hydrostatic balance, a Chelsea filter, a UV torch, a loupe, a darkfield loupe and a spectroscope — step-by-step for each.
Through the refractometer
Drawn from the refractive index above, on a 1.40–1.81 scale. How to take this reading.
Related: Quartz Varieties
Key Differentiators
- Dark green opaque chalcedony with distinctive red/orange spots — diagnostically useful visual appearance
- Red spots caused by iron oxide (hematite/goethite) inclusions
- No other common gem material replicates the green-with-red-spots pattern
- Hardness 6.5–7; SG 2.58–2.64; RI ~1.535
- Primarily used in cabochons, carvings, and intaglios
Common Simulants
- Green glass with inclusions: Isotropic; gas bubbles; SG lower; red spots would be surface-painted not internal. Rare simulant — bloodstone appearance is difficult to fake convincingly.
- Dyed green jasper with surface spots: Examine red spots under 10× — natural spots are irregular, three-dimensional iron oxide concentrations, not surface paint.
Measurement Guides
Identifying a bloodstone? Loupewise walks through these tests in order — RI, SG, fluorescence, and more.
Try Loupewise Free →Studying for the GIA, FGA, or FEEG practical? Bloodstone is one of the 132 species in Loupewise’s drill and exam pool — practice identifying it from its measured properties under timed exam conditions.
Practice exams →