The Black Range

Fluorite/Calcite
From Fluorite Ridge Luna County, NM
Specimen at Mineral Museum New Mexico Institute of Mining and Technology Socorro, New Mexico
Photograph taken on April 6, 2016

When I think of the minerals of the Black Range, I think of three; gold, silver, and fluorite (a.k.a. fluorspar - a term generally used when the material is an industrial or chemical commodity).  The first two I think of as garish and overpriced.  The source of needless destruction throughout the world, the symbol of greed and pain, and the source of our ignorant tendency to place value on things of only nominal use.  Like the value of national currencies and stocks, the price of gold and silver are purely in the heads of the people who have them or want them.  In themselves, they have no particular value.  When civilizations fail and food is short, try buying some wheat with your gold certificate.  Driving this point home is the following quote from “Mineral-Resource Assessment of Luna County, New Mexico“ byMcLemore et al., September 2001 - p. 15 “On October 6, 1942, the U.S. War Department closed all gold and silver mines in the U. S..  Only base metals and other strategic minerals such as tin, tungsten, manganese, beryllium, fluorite, and iron were mined...war ended...as did the ban on gold and silver mining.”  (The latin word, fluere, is the basis for the name fluorite, and means “to flow” a reference to fluorite’s use as a flux in smelting.)  

Fluorite on the other hand has utility and it has inherent beauty.  A fluorite crystal is a thing of beauty, without the intervention of humankind.  CaF2 is its chemical composition, it is one of the halide minerals, and it represents a hardness of 4 on the Mohs scale.  It was mined rather extensively along Fluorite Ridge, Pony Hills, in the extreme southwest of our area of coverage.  See “The Southern Roads” for an extensive discussion about the mineral and its mining in the Fluorite Ridge area.

Both the words fluorescence (coined by George Stokes in 1859) and fluorine are derived from the word fluorite.  The element fluorine is very reactive, forming compounds with almost all of the other elements (including some of the “noble gases”).  Its crystalline structure is typically either cubic (if formed in neutral solutions at less than 350° C when the solution is not supersaturated) or as octahedrons (when there is more acidity and saturation, at higher temperatures).  Impurities of various kinds can cause other crystal shapes.  Fluorite is colorless, but impurities change its hue to many beautiful shades, mostly greens and blues (but also reddish hues).

Because fluorite forms in hydrothermal veins, of which there are many in the Black Range, it is fairly common here.  It is often associated with Calcite, Quartz, and Galena. 

My first experience with fluorite was on a collecting trip as part of a Mineralogy course as a sophomore in college.  We were digging in a nice vein in southern California when I found a nice fluorite crystal about half the size of my fist.  I gave the crystal to the college but kept the image in my mind. 

This is a partial listing of mines where Fluorite was found in the Black Range:

HILLSBORO DISTRICT: Macy Mine 

KINGSTON DISTRICT:  Carbonate Creek Mine - Grey Eagle Mine

CHISE DISTRICT: Cross Mountain Prospects - Concordant Flourspar Mine - Unnamed Prospect - Victorio Prospect

CUCHILLO NEGRO DISTRICT: Bootlegger Mine - Fairview Prospect  - Prospectors Delight Mine

PARAMOUNT CANYON: Beryllium Virgin Claim

SALADO: Salado Prospect

TAYLOR CREEK TIN DISTRICT: 74 Draw Mine

COOKE’S RANGE: Cooke’s Range Manganese District

COOKE’S PEAK DISTRICT: Cooke’s Peak Area - Montezuma Mine - Section 27 Prospect

FLUORITE RIDGE DISTRICT: Goat Ridge Prospect - Grattan Mine - Green Spar Mine - Greenleaf Mine - Hilltop Prospect - Lucky Mine - Sadler Mine - San Juan Mine - Tiptop Prospect - Valley Mine - Whitehill Prospect