Saturday, February 9, 2008

Fool's gold

I was around 9 years old, when I saw the first pyrite specimen in my life, and I remember I was so greatly impressed, that I wanted to go to the site where the person that showed it to me (a neighbor by the name of Javier Garcia) said he had collected the piece from, the "Cerro del Cuatro" (the hill of the four) in Guadalajara, state of Jalisco in Mexico.

From that day, I fell in love with minerals; and soon enough, my dad discovered I had a new hobby, and bought a Mineralogy booklet for the family, which contained, among others, some pictures of perfect pyrite cubes crystals from Rio Tinto, Spain. I was hooked, and eager to learn more and more about pyrite and other minerals. Pyrite was, at any rate, the mineral that changed my life, with its luster and a perfect crystallization. I would've probably be a doctor, or a pilot, but not a geologist otherwise, thanks to Pyrite.

One of the first things I learned about pyrite was that its origin was related to volcanoes, and that it had a funny nickname: "fool's gold," due to its brassy yellow color, and metallic luster resembling gold to some. How many people bought pyrite in lieu of gold just to find later on they have been fooled? maybe a good bunch, but such is life.

Anyhow, let's see what is this fool's gold or pyrite consist of:


Chemical Formula: FeS2
Composition: Iron (Fe) 46.55%; Sulfur (S) 53.45%
Molecular Weight = 119.98 gm
Empirical Formula: Fe2+S2 (Iron sulfide)
Environment: Sedimentary, magmatic, metamorphic, and hydrothermal deposits.
Locality: I collected beautiful crystals from Naica, Chihuahua, and Fresnillo, Zacatecas, as I used to work for Cia. Fresnillo, SA between 1977 and 1980. But pyrite is common on a world wide basis, related to almost any kind of ore deposit.
Name Origin: From the Greek, pyros - fire and lithos - stone or mineral, "stone which strikes fire," in allusion to the sparking produced when iron is struck by a hammer, or by a lump of pyrite

For more technical details, please refer to:

In the meantime, have a great weekend, see you in my next posting.


Oscar Garcia Shelly

No comments: