Lepidocrocite (γ-FeO(OH)), also called esmeraldite or hydrohematite, is an iron oxide-hydroxide mineral.

Lepidocrocite has an orthorhombic crystal structure, a hardness of 5, specific gravity of 4, a submetallic luster and a yellow-brown streak.

It is red to reddish brown and forms when iron-containing substances rust underwater.

The structure of lepidocrocite is similar to the boehmite structure found in bauxite and consists of layered iron(III) oxide octahedra bonded by hydrogen bonding via hydroxide layers.

It was first described in 1813 from the Zlaté Hory polymetallic ore deposit in Moravia, Czech Republic.