Porgandite

Porgandite is a naturally occurring mineral composed primarily of hydrated titanium dioxide. It is a relatively rare member of the perovskite group of minerals. The chemical formula for porgandite is often represented as TiO2·nH2O, indicating its hydrated nature. Its crystal system is typically tetragonal, though well-formed crystals are uncommon. Porgandite is usually found as a secondary mineral, forming through the alteration of primary titanium-bearing minerals like ilmenite and rutile.

The mineral is typically opaque and can range in color from black to brown and reddish-brown. Its luster is often dull to greasy. Porgandite is known for its low hardness, typically ranking around 3 on the Mohs scale, and its specific gravity is generally between 3.5 and 4.0. Due to its hydrated nature, it can lose water upon heating.

Porgandite has been identified in various geological environments, including altered igneous rocks and placer deposits. It is often associated with other titanium minerals. Its discovery and identification have contributed to the understanding of mineral alteration processes and the geological conditions under which titanium minerals form and transform. While not economically significant as a primary source of titanium, its presence can be an indicator of past geological activity.