Calcite Mercenaria clam fossil from Ruck's Pit, Fort Drum, Florida. These are Pleistocene-era hard clams where the original shell material dissolved and was replaced by amber-colored calcite crystals over millions of years. The result is a shell-shaped mass of amber...

Star rose quartz sphere, 30mm in diameter. This sphere displays asterism: direct light from above produces a visible star pattern of four to six rays caused by rutile needle inclusions aligned inside the quartz. The pink color of rose quartz...

Iridescent rainbow pyrite concretion from the Volga River, Ulyanovsk Oblast, Russia, 1.75 by 1.25 inches. The rainbow colors come from thin natural tarnish layers on the pyrite surface that cause different wavelengths of light to interfere with each other, the...

Quartz cluster from the Streep Mine, Namibia, 1.25 by 1 inch with a prominent centerpiece crystal point. Streep Mine quartz is collected specifically for exceptional crystal clarity and well-defined terminations. Multiple transparent points rise from a shared matrix base, each...

Red hematite quartz cluster from Morocco, 4cm by 3cm by 2cm. Hematite deposited on the quartz crystal surfaces during or after their formation, coating them in reddish-brown while leaving the quartz sparkle intact. The result is quartz points that catch...

Herkimer diamond from the Diamond Mountain Mine, Little Falls, New York, 1.25 inches long and 0.75 inches wide. This specimen has hydrocarbon inclusions that create internal rainbows as the crystal is rotated. Ancient organic material sealed inside the crystal during...

Triple cube fluorite specimen from the Yindu Mine, Inner Mongolia, China, 1cm by 1.5cm. Three interlocking cube-shaped crystals in blue-green with a purple core visible through the transparency. The two colors represent two distinct phases of crystal growth. Under UV...

Fluorite specimen from the Yindu Mine, Inner Mongolia, China, 2.2cm by 1.5cm. Vivid green color with a purple core visible through the transparency. Two distinct phases of crystal growth, two colors in the same specimen. Under UV light it transforms...

Fluorite specimen from the Yindu Mine, Inner Mongolia, China, 3cm by 1.2cm. In normal light you see the natural fluorite color. Under UV light it glows an intense blue immediately. Fluorite is the mineral that gave fluorescence its name, and...

Rhynchonellida brachiopod fossil shell from Morocco. Brachiopods have existed for over 500 million years. Superficially similar to clams but not related to mollusks at all. The Rhynchonellida order is recognizable by its strongly ribbed surface, clearly visible on this specimen....

Witch's Wart botryoidal chalcedony specimen from Morocco with a gnarly, grape-like surface texture in earthy brown transitioning to milky white. The bumpy rounded surface forms when chalcedony precipitates from silica-rich solution and individual growth centers develop simultaneously, each one growing...

Tumbled green rainbow fluorite stones, approximately 40 grams each and 1 to 1.25 inches, with natural green-blue base color and purple color zoning. The color zones formed during crystal growth as trace element concentrations fluctuated. More manganese produces more purple....