Spinellide

Spinellide is a rare mineral species that belongs to the spinel group. It was first discovered in 1970 in the Ilimaussaq complex, Greenland, and is named after its chemical composition, which is a magnesium-aluminum oxide with the formula MgAl2O4. Spinellide is typically found in alkaline igneous rocks and carbonatites, and it is often associated with other minerals such as nepheline, sodalite, and apatite.

The mineral is characterized by its dark brown to black color, which is due to the presence of iron impurities. It has a hardness of 8 on the Mohs scale, making it relatively hard and durable. Spinellide has a cubic crystal structure and typically forms octahedral crystals, although it can also occur in massive or granular forms.

Spinellide is not considered to be of significant economic value due to its rarity and the fact that it is often found in small quantities. However, it is of interest to mineralogists and collectors due to its unique chemical composition and the geological settings in which it is found. The mineral has been studied for its potential use in high-temperature applications, such as in the production of refractory materials, due to its high melting point and resistance to thermal shock.