Description

Pyrite, or Iron Pyrite, is an Iron sulfide with isometric Crystals that usually appear as cubes.  It is brittle and can break or powder easily.  Its metallic luster and brass yellow hue have earned it the nickname of “fool’s gold” due to many miners mistaken it for the real thing.  Ironically, small quantities of actual gold are sometimes found in Pyrite.  It is the most common of the sulfide minerals and is usually found with other sulfides or oxides in Quartz veins, sedimentary or metamorphic rocks. 

The mineral marcasite, sometimes called “white iron pyrite”, is iron sulfide with orthorhombic crystal structure. It is physically and crystallographically distinct from pyrite, which is iron sulfide with cubic crystal structure. Both structures do have in common that they contain the disulfide having a short bonding distance between the sulfur atoms. Marcasite is lighter and more brittle than pyrite. Specimens of marcasite often crumble and break up due to the unstable crystal structure.