Chevkinite

Chevkinite is a rare silicate mineral with the chemical formula (Ce,La,Ca)4(Fe3+,Fe2+)2(Ti,Nb)3Si4O22. It is a member of the chevkinite group of minerals, which are characterized by their complex crystal structure and presence of rare earth elements. Chevkinite typically occurs as prismatic or tabular crystals, often dark brown to black in color. It is known for its relatively high density.

The mineral was first discovered in the Ilmen Mountains of Russia in 1832 and was named after Grigory Nikolaevich Chevkin, a Russian mining engineer. Chevkinite is found in a variety of geological settings, including alkaline igneous rocks, metamorphic rocks, and placer deposits. It is often associated with other rare earth minerals such as monazite and bastnäsite, as well as titanite and zircon.

While not a major ore of any element, chevkinite is of scientific interest due to its complex composition and its potential role in understanding the geochemistry of rare earth elements. Its presence can indicate specific geological conditions during rock formation. Due to its rarity, occurrences of chevkinite are often noted and studied by mineralogists and geologists.