The mineral pyrite, or iron pyrite, also known as fool’s gold, is an iron sulfide with the chemical formula FeS2 (iron(II) disulfide). Pyrite is considered the most common of the sulfide minerals.
The specimen was found in a specific mine in Navajun, Spain. This occurrence, developed and operated solely to produce pyrite specimens, is called the Mina Ampliación a Vitoria (known as the Victoria Mine)
The best cubic crystals of pyrite of the world are extracted from this mine. The biggest crystal so far had a size of 19 cm and weighed 9.5 kg.