Fluorite from Sweet Home Mine, Colorado, USA

When a specimen is not a single crystal, we turn to its paragenesis for insights. This tiny piece reveals an array of fascinating features when I really looked into it.

A blue cubic fluorite, within a textbook, colourless rhombic-dodecahedral fluorite. Some of fluorapatite crystals and portions of rhodochrosite are included within and embedded in the fluorite, suggesting that fluorite was likely the final phase to crystallise. The earliest solid appears to be sphalerite, as all subsequent minerals grew upon it.

While geochemistry helps us unravel geological processes, geology at its core is grounded in observation. Every interpretation should begin with careful observation, rather than relying solely on computer models and proclaiming, in effect, that “the Earth is flat.”

Fluorite and fluorapatite on Rhodochrosite and sphalerite found in 1970s, 1.6cm, Sweet Home Mine, Detroit City Claim Block, Mount Bross, Alma Mining District, Park County, Colorado, USA

Jingnan (Tom) Zhang Coll & Photo