Pyrite

Large brass-yellow cube of euhedral Pyrite with striations on the crystal faces. Crystal size: 1.0 cm x 1.1 cm x 1.2 cm. Pyrite (FeS2) can be pale yellow or brass-yellow in colour and is often tarnished black or brown. Lustre is usually metallic but can also be iridescent and streak is greenish black. Hardness is 6 to 6 1/2. Pyrite usually occurs as cubic form or pyritohedrons with parallel striations on the faces. Pyrite can also be fine to coarse granular, disseminated or massive.