Mineral Type - Jasper

A variety of Chalcedony, which is a variety of Quartz.

Jasper is usually considered as Chalcedony; sometimes, however, scientists put it in a group by itself within the quartz group because of its grainy structure.
The name jasper is derived from the Greek and means "spotted stone".
The finely grained, dense jasper contains up to 20 percent foreign materials, which determine its colour, streak, and appearance. Uniformly coloured jasper is rare, usually it is multicolored, striped, or flamed. Sometimes jasper can be grown together with agate or opal. There is also some fossilized material.

Physical Properties

Transparency: Opaque
Colour: All colours, valuable jaspers have complex combinations strips and spots. Very intricate patterns
Hardness: 6.5 to 7 on Mohs scale
Cleavage: None
Fracture: Conchoidal, Splintery

Chemical Properties

Formula: SiO2

Crystallography

Crystal System: Trigonal

Synonyms

Imperial Jasper

Varieties

Ball Jasper, Bayate, Chrysojasper, Creolite, Dallasite, Darlingite, Egyptian Jasper, Kinradite, Obicular Jasper, Owyhee Jasper, Pastelite, Quetzalitztli, Riband Jasper, Vogelaugenjaspis, and Wilkite