This texture was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
A filter I did that simulates Magnetite. Adjustable color, reflectivity, crystal size-AND CRYSTAL SHAPE MAPPING.
Impurity color and Impurity controls adds impurities into crystal
Magnetite, Iron Oxide, Fe3O4, Iron, Crystalline, Loadstone, Tetrahedron, Crystal mapping, Crystal, Iron Ore, Impure, Impurity