Fluorite

Description

Fluorite is the defining mineral as a hardness of 4 on the Mohs scale, and its specific gravity is ~3.175. Fluorite forms as a late-crystallizing mineral in felsic igneous rocks typically through hydrothermal activity, and it’s typical in granitic pegmatites.

Named in 1797 by Carlo Antonio Galeani Napione from the Latin, fluere = “to flow” (for its use as a flux). The mineral is used as a flux in iron smelting to decrease the viscosity of slag. The term flux comes from the Latin adjective fluxus, meaning flowing, loose, slack. The mineral fluorite was originally termed fluorospar and was first discussed in print in a 1530 work Bermannvs sive de re metallica dialogus [Bermannus; or a dialogue about the nature of metals], by Georgius Agricola, as a mineral noted for its usefulness as a flux.

The term fluorescence is derived from fluorite, which will often markedly exhibit this effect. The element fluorine also derives its name from fluorite, a major source of the element, which makes this a perfect sample for your element collection!