Curio Cabinet: Fluorite
The Curio Cabinet series (#curioTuesday) is published biweekly, featuring an artifact of natural or cultural history and a brief selection of nifty facts. Curio Cabinet celebrates the history of curio collections, the roots of which played a part in the globalization of learning and scientific knowledge. Learn more here.
Today’s curio: fluorite
Origin: found worldwide
Size: approx. 2 in long x 1 in tall
Fluorite is the most common rock you don’t know about. Actually, I take that back – you probably already know a bit about it without realizing it. Deposited by hydrothermal processes and sometimes found in limestones and dolomites, this mineral is also called fluorspar, and gives us the root of the word “fluorescence” for its neato ability to glow blue under UV light.
Fluorite is the only common mineral with four directions of perfect cleavage, meaning that it can create these uber-awesome natural octahedrons.
Color is not a good way to identify fluorite, although common colors include purple, green, yellow, or a banded mixture of colors. Here’s a Google images snapshot of just some of the different colors fluorite comes in:
We use fluorite in a number of ways:
1. Lenses. Because of its low dispersal and low refractive qualities, fluorite makes for good microscope and telescope lenses.
2. Fluoride. Fluoride is a chemical derived from fluorite that is said to protect tooth enamel.
3. Iron, steel, and the production of other metals. Fluorspar is added to the metallurgic process to help remove impurities; between 20 and 60 pounds of fluorspar is used for every ton of metal produced!
We use it in the production of fluorocarbon derivatives in solvents, refrigerants, and anesthetics. Remember chlorofluorocarbons, the toxic greenhouse gas that used to pump out of every fridge and air conditioner? Yeah, we failed on that one.
Fluorite is also used in a lot of jewelry: it’s turned into beads and tumbled gemstones and cabochons for its variety of light colors and transparency. It’s too soft to be used more widely (rates a 4 on the Mohs scale) but you have to admit, it does make for some pretty embellishments. I think my favorite is that reddish-pink on in the top left.