innoite

Innoite is a mineral consisting of the element indium in its native, elemental form. It is extremely rare and has been found in only a few locations worldwide. Chemically, it is metallic indium with a purity that can vary. Innoite crystallizes in the cubic system, typically forming small, octahedral crystals. Its color is a bright, silvery white, and it possesses a metallic luster. The mineral is relatively soft, with a Mohs hardness of around 1.5, and has a high density.

The discovery of innoite is closely linked to the broader exploration and identification of indium-bearing minerals. Indium itself was discovered in 1863 by Ferdinand Reich and Hieronymus Theodor Richter and was named for the bright indigo lines in its spectral emission. Native indium, or innoite, was identified later as deposits were found where the elemental form could exist. Its rarity means it is not a significant commercial source of indium, which is primarily extracted from other minerals like sphalerite and chalcopyrite. Innoite is of scientific interest to mineralogists and geologists studying the natural occurrence of elements.