7.9" Polished Berber Agate Section - Sidi Rahal, Morocco

Berber agate, also known by some as Antelope Agate, is the trade name for an agate that is collected near Sidi Rahal, Morocco. They occur within Triassic basaltoids and have characteristic coloration and internal structures that make them easily identifiable by collectors. They typically feature a pink outer rim that is composed of opaque opal-CT, with red to red-brown interior layers that gain their color from iron impurities (goethite and hematite). The centers of these nodules are often blue-gray/white-grey and contain small amounts of moganite.

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 rock and/or fossils, resulting in deposition of the silica along the walls of the rock. This process can result in banding patterns as the composition and impurities of the fluids change over time. These banding patterns can either form as flat layers or rounded layers, depending on the surfaces available for deposition.