Michiganite is a noun that refers to a variety of the mineral pumpellyite found in the state of Michigan, USA. It is a member of the pumpellyite group and crystallizes in the monoclinic crystal system. This mineral is usually found in metamorphic rocks and forms as a result of regional metamorphism caused by the tectonic activity occurring in the area.
Michiganite typically occurs as compact aggregates or fibrous masses in various colors such as green, brown, or black. It has a vitreous to dull luster and a Mohs hardness of approximately 5 to 6. The mineral is translucent to opaque and has a specific gravity ranging from about 3 to 3.5.
In terms of its chemical composition, Michiganite is primarily composed of calcium, aluminum, iron, magnesium, and silicon. It often forms as a product of the alteration of other minerals, typically in low-grade metamorphic conditions.
As the name suggests, Michiganite is predominantly found in the state of Michigan, particularly in the Upper Peninsula. It can also be found in certain other localities around the world, such as New Jersey and Canada.
Due to its distinctive crystal structure and unique occurrence, Michiganite has drawn interest from mineral collectors and researchers alike. Its presence in certain geological formations can provide valuable insights into the conditions under which these rocks were formed.
