Jasper

Jasper, an aggregate of microgranular quartz and/or chalcedony and other mineral phases, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron inclusions.

The name means “spotted or speckled stone”, and derived via Old French jaspre (variant of Anglo-Norman jaspe) and Latin iaspidem.

Jasper is an opaque rock of virtually any color stemming from the mineral content of the original sediments or ash. Patterns arise during the consolidation process forming flow and depositional patterns in the original silica rich sediment or volcanic ash. Hydrothermal circulation generally thought to required in the formation of jasper.