7.05" Polished Prineville Reservoir Moss Agate Slab - Oregon

Moss agate is a variety of chalcedony, frequently containing colorful green, red, or brown mineral inclusions similar to fluffy patches of moss. They can also have brown to black dendrites of iron or manganese oxides.

Agate is a variety of microcrystalline quartz (chalcedony) that displays translucence and, in some cases, banding. Agate primarily forms when silica-rich fluids fill pockets within rocks and/or fossils, depositing the silica along the walls of the rock. This process can result in banding patterns, as the compositions and impurities of these depositing fluids change over time. These banding patterns can either form as flat layers, creating linear patterns known as waterline agate, or as rounded layers, forming more common ring-like patterns. These patterns depend on the surfaces available for deposition.