Quartz SiO2
Sawpit Gulch, Kingston Mining District,
Sierra County, NM
Specimen at
Mineral Museum
New Mexico Institute of Mining and Technology
Socorro, New Mexico
Photograph taken on April 6, 2016.
Quartz, SiO2, meant a lot to the miners of the Black Range, where there was quartz there was likely to be all sorts of goodies; gold, silver, lead.... Quartz is found in many geologic settings and is a component of many rock types (granite, for instance). You may, or may not, know it as κρύσταλλος, the name given it by Theophrastus in about 325 BCE.
The photograph above is from a specimen mined in Sawpit Gulch, north of Kingston - follow the link to our description of a hike in the area.
Quartz comes in a number of varieties, often descriptors relating to color created by“impurities”. Within a particular variety, there can be a significant color gradient, both hue and intensity. The Amethyst specimen pictured here (below) is an excellent example of quartz color. But when we say a significant color gradient, we mean it, from clear to…. See, for example, the specimen below from the Black Knife Mine of the Cuchillo Negro District in Sierra County, New Mexico, the white material is Calcite. (In our blog on Calcite we discussed this tendency of Calcite to cover anything and everything.) There are more variety names given to Quartz than to any other mineral. Chalcedony is a variety of Quartz but is often treated in “the trade” as if it were a distinct mineral.
What I often tell beginning birdwatchers is that they should really learn the common birds - really learn them. Then when something different shows up they will recognize it as different from the very beginning - and pay attention. Quartz is like that, learn quartz and you can dispense with a lot of rock. It is a hard rock (Mohs scale of 7) and has a specific gravity of 2.7, with practice you can recognize the specific gravity of a pure specimen quickly.
For a partial listing of mines where Quartz was found in the Black Range:
HILLSBORO DISTRICT: Big Chief Mine in Percha Creek - Bonanza Mine - Chance Mine - Copper Flat (Sternberg Shaft) - Copper Flat Claims - Garfield Butler Group - Macy Mine - Petroglyph Mine - Unnamed
GEORGETOWN DISTRICT: Mimbres Mine - Copper Rose Mine
KINGSTON DISTRICT: Ladrone Gulch Camp (Brush Heap MIne) - Silver Mine Group - Tall Pine Mine
CHLORIDE DISTRICT: US Treasury Mine - Alaska Group (incl. Amethyst) - Little Granite Mountain - Sheep Canyon - Illinois Mine (incl. Amethyst) - Bald Eagle Mine - Pye Lode - Black Mountain Group - Great Republic Mine (incl. Amethyst)
CHISE DISTRICT: Concordant Fluorspar Mine - Unnamed Prospect
CUCHILLO NEGRO DISTRICT: Prospectors Delight Mine
COOKE’S PEAK DISTRICT: Jose District - Faywood Mine
HERMOSA DISTRICT: Nana Mine
PARAMOUNT CANYON: Beryllium Virgin Claim
TAYLOR CREEK TIN DISTRICT: Alexander Mine - Round Mountain - Squaw Creek Mine
TIERRA BLANCA DISTRICT: Berrenda Creek Prospects - Latham Mine - Log Cabin Mine - Lookout Mine (incl. Amethyst)
FLUORITE RIDGE DISTRICT: Goat Ridge Prospect - Grattan Mine - Greenleaf Mine - San Juan Mine - Valley Mine - White Bluff Prospect