lepidokrocite

Lepidocrocite is a naturally occurring iron oxyhydroxide mineral with the chemical formula γ-Fe O(OH). It is one of the common polymorphs of iron oxyhydroxide, alongside goethite and feroxyhyte. Lepidocrocite typically forms in environments where iron-rich solutions are exposed to oxidizing conditions, such as in bogs, marshes, and sedimentary rocks. It is also found as a secondary mineral in the weathering crusts of iron-bearing rocks and as a component of rust.

The mineral is characterized by its distinct fibrous or scaly appearance, which gives it its name, derived from the Greek words "lepis" meaning scale and "krokos" meaning saffron, referring to its color. Lepidocrocite commonly occurs as thin, platy crystals or as a powdery coating. Its color ranges from reddish-brown to orange.

In terms of physical properties, lepidocrocite is relatively soft, with a Mohs hardness of about 5. It has a specific gravity of approximately 3.4. It is insoluble in water but will dissolve in strong acids. Lepidocrocite is an important indicator mineral in paleoclimate studies, as its formation is sensitive to environmental conditions. It can also be a component of iron ores and is sometimes found associated with other iron minerals like goethite and hematite. Its presence can influence the geochemistry of soils and aquatic environments.