Dallasite
A volcanic breccia, it contains well-defined, thin, rectangular chunks of green or brown lava set in a silicifed matrix, can be classed as a type of jasper.
Named for Dallas Road, Victoria, British Columbia, Canada, which runs along the southern tip of the city where it was found.
Named for Dallas Road, Victoria, British Columbia, Canada, which runs along the southern tip of the city where it was found.
| General Information | |
|---|---|
| A variety or type of: | Jasper, which is a variety of Chalcedony, which is a variety of Quartz |
| Physical Properties of Dallasite | |
| Mohs Hardness | 6.5 to 7, Blue Chart Gem Identification (2010) |
| Specific Gravity | 2.58 to 2.91, Blue Chart Gem Identification (2010) |
| Optical Properties of Dallasite | |
| Refractive Index | 1.540 (+/-), Blue Chart Gem Identification (2010) |
| Optical Character | Uniaxial/+, Gemmological Tables (2004) |
| Birefringence | 0.008 to 0.010, Gemmological Tables (2004) |
| Colour | |
| Colour (General) | Green, black, Management Team (2012) |
| Crystallography of Dallasite | |
| Crystal System | Trigonal, Gemmological Tables (2004) |
| Further Information | |
| Mineral information: | Dallasite information at mindat.org |