1.8" Vivid Blue, Cut/Polished Azurite Nodule - Siberia

This is an incredibly vivid, blue azurite nodule that has been cut in half and polished. One half of the nodule is included. The green color can be attributed to the formation of malachite in association with the blue azurite. These vibrant nodules/geodes come from Poteryaevskoe Mine near Rudnyi Altai in Siberia.

Azurite is a copper carbonate hydroxide mineral with a chemical composition of Cu3(CO3)2(OH)2. It is best known for it's beautiful and vibrant blue appearance, typically forming with other colorful, copper rich minerals.

Azurite and malachite are known to form in union with each other, for their chemical makeup is very similar. In fact, the presence of more or less water in the location of formation, is enough to determine whether an abundance of malachite over azurite, or vise-versa, will accumulate.

Malachite is a dark green, copper based mineral with the formula Cu2CO3(OH)2. It often forms botryoidal masses in fractures deep underground where the water table or hydrothermal fluids provide the means for chemical precipitation. It rarely forms crystals and it is often associated with another copper based mineral, like azurite. It was used as a mineral pigment in green paints from antiquity until about 1800.
Azurite & Malachite
Poteryaevskoe Mine, Rudnyi Altai, Siberia, Russia
Polished face 1.8x1.65", .47" thick