Bloodstone (Heliotrope)
Bloodstone is an opaque, dark-green
Chalcedony with red spots. An old name still used in Europe is heliotrope (Greek - sun turner). Used often as seals for men's rings and for other ornamental objects.
In the trade, the term blood jasper is sometimes used. Bloodstone, however, is not a
jasper at all, even though a radial structure with spherical aggregates can simulate a grainy appearance.
| General Information |
|---|
| A variety or type of: | Chalcedony, which is a variety of Quartz |
|---|
| Other Names/Trade Names: | |
|---|
| Chemical Formula | Arthur Thomas, Gemstones (2009) |
|---|
| Physical Properties of Bloodstone |
|---|
| Mohs Hardness | 6.5 to 7Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
|---|
| Specific Gravity | 2.55 to 2.70Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
|---|
| Optical Properties of Bloodstone |
|---|
| Refractive Index | 1.530 to 1.543Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
|---|
| Optical Character | Uniaxial/+Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
|---|
| Birefringence | 0.003 to 0.009Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
|---|
| Colour |
|---|
| Colour (General) | Dark green/greenish-blue with small red blood-like spotsGemdat.org, Management Team (2012) |
|---|
| Causes of Colour | Particles of chlorite or included hornblende needles cause the green color. Red spots are caused by iron oxide.Walter Schumann, Gemstones of the world (2001) |
|---|
| Transparency | Translucent,OpaqueHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
|---|
| Lustre | Waxy,ResinousArthur Thomas, Gemstones (2009) |
|---|
| Crystallography of Bloodstone |
|---|
| Crystal System | TrigonalUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
|---|
| Habit | Fibrous to grained aggregateUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
|---|
| Further Information |
|---|
| Mineral information: | Bloodstone information at mindat.org |
|---|
| Significant Gem Localities |
|---|
| USA | | |
| Symons, Henry Heilbronner (1940), Quartz gem stones of California: Rocks & Minerals: 15: 41; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 317. | |
| Symons, Henry Heilbronner (1940), Quartz gem stones of California: Rocks & Minerals: 15: 41; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 318. | |
| U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
|
|
