Jasper
What is Jasper?
Jasper is an opaque variety of chalcedony, and it comes in a multitude of colors including red, yellow, and brown. It’s primarily found in India, Russia, and the U.S. Jasper is known for its unique patterns and is often used as a gemstone.
Jasper is a colorful gemstone that comes in various patterns and hues. Its unique appearance makes it a popular choice for jewelry and decorative items, especially beads, pendants, and cabochons.
Chemical Classification | Inorganic - Silicate (Chalcedony) |
Color | Many colors including red, yellow, brown, green, and occasionally blue, often mottled or striped. |
Streak | White |
Luster | Dull to vitreous when polished. |
Transparency | Opaque. |
Occurrence | Worldwide, including significant sources in India, Russia, and the USA. |
Formation | Usually forms from volcanic ash or fine silicate mud, solidifying over time under heavy pressure. |
Diaphaneity | Opaque |
Cleavage | None |
Mohs Hardness | 6.5 to 7 |
Specific Gravity | Approximately 2.5 to 2.9. |
Diagnostic Properties | Opaque, often red or banded. |
Chemical Composition | SiO2 |
Pleochroism | Does not display pleochroism. |
Crystal System | Hexagonal (variety of Quartz) |
Optical Properties | Uniaxial (+) |
Refractive Index | 1.530 - 1.539 |
Birefringence | 0.009 |
2V angle | Measured: 78° to 82° |
Dispersion | Low. |