QUARTZ, CALCITE with MICROSCOPIC SIZED PYRITE Renison Bel Mine TASMANIA (small cabinet) (Copy)

What appears to be dust or dirt on the botryoidal calcite is actually pyrite. Microscopic crystals in their thousands scattered throughout the specimen. Under 365nm UV the larger calcite turns nicely soft pink.

Pyrite, commonly referred to as fool's gold, is an iron sulfide with the chemical formula FeS2, also known as iron (II) disulfide. It is the most prevalent sulfide mineral found in nature.

Quartz is a robust crystalline mineral made up of silica, or silicon dioxide. Its structure consists of a continuous arrangement of SiO4 silicon-oxygen tetrahedra, where each oxygen atom is shared between two tetrahedra, resulting in the chemical formula SiO2. This classification places quartz as a framework silicate mineral in terms of structure and as an oxide mineral in terms of composition. It ranks as the second most prevalent mineral in the continental crust of Earth, following feldspar.