6.5 - 7.0 on the Mohs scale.

Worldwide. A member of the chalcedony family (micro-crystalline quartz).

Agate is a banded colored stone found in nodular masses associated with volcanic lavas. The curved banding is distinct from other forms of chalcedony. Agate, being porous, is often dyed or stained. Large agates are often cut in half and dyed to form attractive bookends. Agate occurs in a variety of forms, including petrified wood, which has had it's organic matter replaced by agate.

Agate is often dyed with bright colors.

More information on gemstone enhancements.

Agate is a member of the Chalcedony gemstone family.