ferrugi
Ferrugi is a rare and distinctive mineral that is primarily composed of iron and oxygen, with the chemical formula FeO. It is a member of the spinel group of minerals and is known for its distinctive reddish-brown color, which is due to the presence of iron oxide. Ferrugi is typically found in metamorphic rocks, particularly in contact metamorphic zones around igneous intrusions, where it forms as a result of the alteration of iron-rich minerals.
The mineral is often associated with other iron oxides and hydroxides, such as hematite and goethite, and
Ferrugi is also of interest to mineral collectors and enthusiasts due to its distinctive appearance and the