Bloodstone
Bloodstone, also known as Heliotrope, is a type of Chalcedony which is a type of cryptocrystalline, or fine-grained, Quartz with a fibrous microstructure. This type of material is also called Plasma. Plasma is a microfibrous type of Chalcedony colored various shades of green by densely packed fibrous Actinolite crystals and including blood-red to orange spots of iron oxides or red Jasper that resemble blood spots. This material is always opaque and usually found as cabochons but may also be faceted. It is very attractive with its “blood” spots on a deep green background.
Bloodstone is found in India, Brazil and South Africa and more recently very fine examples are coming from Madagascar.
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Category: |
Mineral |
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Chemical Formula: |
SiO2 |
| Silicon Dioxide | |
| Molecular Weight: | 60.08 gm |
| Composition: | Silicon | 46.74 % | Si | 100.00 % | SiO2 |
| Oxygen | 53.26 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE | |||
| Crystallography: | Trigonal – Trapezoidal |
| Crystal Habit: | Widely variable; but typically long prismatic with steep pyramidal terminations, but may be short prismatic to nearly bipyramidal; fibrous (Agate & Chalcedony) |
| Twinning: | Very common, penetration twins on the Dauphiné law, about [0001], and the Brazil law, with [1120] as contact plane; contact twins on the Japan law, with [1122] as contact plane, may be repeated; and several other laws. |
| Cleavage: | Indistinct on {0110} |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 7.0 |
| Density: | 2.60 – 2.65 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Various shades of Green with Blood-Red to Orange spots |
| Transparency: | Opaque |
| Luster: | Vitreous |
| Refractive Index: | 1.543 – 1.554 Uniaxial ( + ) |
| Birefringence: | 0.0090 |
| Dispersion: | 0.013 (low) |
| Pleochroism: |
None |
