1.05" Sparkling Blue Azurite Crystals on Smithsonite - Congo

Azurite is a copper carbonate hydroxide mineral best known for its beautiful and vibrant blue appearance. Azurite typically forms in nodular formations with other colorful, copper-rich minerals. It is a secondary mineral that precipitated in pores, crevices, and caverns from water with high concentrations of carbon dioxide.

Azurite and malachite are known to form in union with each other since 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.

Smithsonite forms in earthy botryoidal masses, sometimes forming grape-like structures. It can be found as a secondary mineral in oxidation zones of zinc ore deposits, in some sedimentary deposits, and as an oxidation product of sphalerite. The general chemical formula of smithsonite is ZnCO3, however Fe (iron), Mg (magnesium), Ca (calcium), Cd (cadmium), Cu (copper), and Co (cobalt) can take the place of Zn (zinc). This potential for elemental variation results in smithsonite's wide variety of colors, including blue, green, yellow, orange, pink, purple, brown, gray, white, and colorless.