Silicon dioxide, usually with impurities of iron oxides or organic substances.
Color
Brown, yellow, orange, red, green, or blue. May also refer to any form of opaque Chalcedony in all colors. Jasper is usually multicolored or banded.
Streak
White
Hardness
6.5 - 7
Crystal System
Hexagonal
Crystal Forms and Aggregates
Jasper is a microcrystalline form of the mineral Quartz, and does not occur in visible crystals. It most often is in massive form, but may also be botryoidal, mammilary, and stalactitic formations, as smooth rounded pebbles, and as nodules.
Transparency
Opaque
Specific Gravity
2.7 - 2.7
Luster
Vitreous
Cleavage
None
Fracture
Conchoidal
Tenacity
Brittle
Other ID Marks
1) Sometimes fluorescent.
2) Triboluminescent
3) Piezoelectric