A cluster of sharp, mirror-bright pyrite crystals out of the Peruvian Andes.
The mine most of this material comes from sits above 4,000 metres in Ancash. It was found in 1721, worked, abandoned, and left alone for well over two centuries before being reopened in the 1960s. A Japanese company bought it in 1964 and still runs it today, for lead and zinc.
The pyrite is a by-product. Nobody is mining for it, and it has no real value as ore next to what they are actually extracting, yet the mine is thought to have produced more mineral specimens by weight than any other single mine anywhere. Everything on this piece came up a shaft because someone decided it was worth more intact than crushed.
Mineral: Pyrite (iron sulfide, FeS₂)
Crystal system: Cubic
Origin: Peru
Hardness: 6 to 6.5 on the Mohs scale; hard, but brittle, and crystal edges chip rather than scratch
Treatment: None
Dimensions: 5.2 x 3.5 x 7.5 cm
Weight: 735 g Note: Keep it somewhere dry. Pyrite reacts slowly with oxygen and moisture, and the reaction produces sulphuric acid, which is what damages a neglected specimen over time. Do not seal or varnish it. That traps moisture in rather than keeping it out, and makes the problem worse.
You will receive the exact piece photographed.