A microcrystallized quartz rendered opaque and colored by the presence of clay or iron oxides.
Jasper occurs in many different shades, including multi-colored and patterned specimens.
For this reason it is usually known under a variety of names that evoke its origin or appearance: riband, jasp-agate, Egyptian, leopard, etc.
One of the most coveted forms of jasper is the heliotrope, which has a uniform green shade, speckled with red spots of iron oxide which resemble drops of blood, hence its other name of bloodjasper. It has often been used for glyptics in Christian art. Readily available, jasper has been used for ornamental purposes (jewelry, amulets, decorative objects) by civilizations everywhere since prehistoric times. Hardness: 6.5 to 7. Birthstone of natives to Aries. Russia, India, Sicily, United States, Africa.