Today's letter is "F"

Today’s topic starts with the letter “F”.

Fluorite is the choice for today.  Fluorite is a colorful mineral and can range in color from blue, green, yellow, brown, purple and rainbow which have bands of differing hues.  The colors depend upon several factors including any impurities, exposure to radiation and the size of the color centers.  (Color centers are created when the mineral crystal is exposed to heat and the ions rearrange themselves leaving behind some electrons.  I think I have that right.  I am not a chemist or biologist or anyone that works with minerals.) Many stones are fluorescent which means that they glow when exposed to ultraviolet light. 

Fluorescing fluorite from Boltsburn Mine Weardale, North Pennines, County Durham, England, UK.

Fluorite is mined in Australia, South America, China, Europe, and North America.  It is the state mineral of Illinois and was made such when the state was the largest producer in the United States.  The last mine there closed in 1995. 

This is a soft stone and has to be treated with care or it will break. 

Fluorite crystals on display at the Cullen Hall of Gems and Minerals, Houston Museum of Natural Science

Fluorite is a major source of hydrogen fluoride which is used to produce a wide range of materials.  A low grade of fluorite is used as a flux to lower the melting point of raw materials in steel production to aid in the removal of impurities.  A medium grade is used in making opalescent glass, enamels, and cooking utensils.  High grade fluorite is used to make hydrogen fluoride and hydrofluoric acid.

I hope you are enjoying learning about these gemstones and minerals.  I still have more coming up for the next nineteen days.  Stop by and see if I can make it all the way through the alphabet.

Carolyn