Quartz is a silicon dioxide mineral belonging to the Quartz group. Quartz is the most abundant mineral on Earth, found in most geological environments and a component in most rock types. Quartz varieties include microcrystalline Chalcedony types (each variety has its own page); and macrocrystalline Quartz types, which is clear in its purest form. Impure varieties include Amethyst, Citrine, Smokey Quartz and the massive variety Rose Quartz (each variety has its own page).
Quartz, also known as Rock Crystal, is further named after the growth types Phantom, Elestial, Double Terminated; locality Tibetan Black, Herkimer Diamond; inclusions Rutile, Tourmalinated; artificial coatings Cobalt Aura, Opal Aura; and synthetic production Siberian Blue, Green; and that's to name but a few (each has its own page).
Cobalt Aura Quartz is the trade name of an attractive metallic blue Quartz. The surface treatment is proprietary, but is believed to involve a Cobalt based coating that is deposited by spraying at high temperatures. Cobalt Aura Quartz has a metallic sheen and a substantial dichroic appearance. The surface coating cannot be removed once applied.
Fine Cobalt Aura clusters make desirable collectors pieces.