It starts out looking golden as iron pyrite (iron disulfide) seen pictured above, but when exposed to water and oxygen it will turn into iron oxides and hydroxides, like rust or the limonite on the lower photo. So much for golden dreams, but it did excite the imagination of the kid rockhound when I got these “treasures” when I was young. Wow! I had a rust-like rock that still held the crystal form of fool’s gold that it once was.
Unfortunately, this collector’s curiosity also has a dark side (yes, pun intended). Pyrites are sometimes present in materials used in concrete, drywall, and other construction materials. When saturated with water and certain bacteria that accelerate the oxidation of pyrite, it can cause serious weakening of structures and drywall with catastrophic consequence. Now, such construction materials must be certified free of pyrite and similar minerals; that’s the kind of “gold” that no one wants to fool with.
#pyrite #foolsgold #limonite #rust
Eskildoodle Photos and Feelings 