Specimens from the Gregory Crenko Illinois Fluorite Collection
Greg's interest in minerals started at about age 10 when he found Quartz crystals in local corn fields. Greg has been active in mineral collecting and trading for the past 30 years. At one time he was an avid field collector and found the first confirmed finding of Caffersite (Smithsonian did the analysis) in the Sawtooth Mountains batholith of Idaho.
With good foresight he decided, early on, to specialize in Southern Illinois Fluorites when they were more available. He realized there was good opportunity as a dealer of collectible mineral specimens due to the development of the internet and increasing competition for high quality world wide minerals. He is the owner of Top Shelf Minerals.
Greg is an accomplished self taught guitar player and songwriter and has toured with some national acts. As seen in the photo, he is also an animal lover.
I am pleased to offer this first installment of fine Illinois Fluorite specimens from his collection, which I recently acquired. There will be further installments over the coming months.
#GC - 002
Lustrous dark golden Fluorite crystal cluster with outer purple zoning. In fine condition.
Beautiful, purple, translucent,stepped face Fluorite crystals with Galena and Sphalerite. Very presentable from both sides and in fine condition.
Dark golden Fluorite crystals with some outer purple zoning and accompanying white Barite.
Very aesthetic cluster of purple-blue Fluorite crystals with some stepping formation and beveled edges. In very good condition.
Yellow Fluorite crystal cluster with wonderful bluish zoning and adornment of Calcite crystals.
Very nice bi-colored purple and dark yellow Fluorite crystal cluster.
Nice size specimen of dark purple Fluorite cubes perched aesthetically on a plate of Sphalerite crystals.
Well balanced cluster of translucent golden Fluorite crystals with some outer purplish zoning. In fine condition.
Lustrous, rootbeer colored Fluorite crystal cluster with dark outer zoning. In fine condition. The upper left corner of the central large crystal is not damaged, but has a whitish color due to natural internal fractures.
Very pretty cluster of yellow Fluorite crystals with pronounced bluish zoning.
Superb yellow Fluorite crystal cluster with dots of purple and adorning Calcite crystals.
Large blue Fluorite crystal with multiple zones of dark blue-purple. Presentable from several sides. In very good condition.
Fine specimen of gemmy yellow Fluorite cubes with lighter, almost glassy outer zoning on Sphalerite.
An aesthetic cluster of Fluorite crystals with a raspberry-purple and yellow coloration.
Nice size cluster of lustrous golden Fluorite crystals with outer purple zoning.
Golden Fluorite crystals with light purple outer zoning and aesthetic surface texture from "natural" acid etching.
Wonderful, honey colored Fluorite crystals on Sphalerite. Has some purple outer zoning.
Stunning blue Fluorite crystal cluster with Calcite.
In fine condition.
Golden Fluorite crystal cluster with splashs of raspberry-purple coloration.
Nice plate of dark purple Fluorite crystals.
Gemmy yellow Fluorite crystals with light blue outer zoning and with Barite scattered on the surface of the crystals. Even better in person !!
Aestehtic dark blue to light purple Fluorite cubes with dark purple zoning.
Very attractive grouping of yellow Fluorite crystals nicely contrasted by surrounding very pale yellow to almost clear outer crystals.
Excellent specimen of the most sought after true blue variety of Illinois Fluorite with some complimenting double terminated Calcite crystals. In fine condition.
Sizable plate of yellow-golden Fluorite crystals with some bluish zoning and surface texturing from "natural" acid etching.
Gorgeous, well balanced cluster of blue Fluorite crystals.
Pretty crystal of golden Fluorite with a thick teal blue outer zone.
Large plate of lovely purple Fluorite crystals with Chalcopyrite.
Very nice cluster of golden Fluorite with some outer zoning.
Fluorite, the official Illinois State Mineral, was discovered in 1839 by James Anderson while digging a well near Fairview Landing one half mile SW of this site. Fluorite was a waste product until the steel industry began using the mineral in their open hearth process in 1888. Rosiclare Lead and Fluorspar Mining Co., located 255 yards NW of this site, was the first major producer of Fluorite. The largest and deepest Fluorite mines in the world are located in Hardin County. For many years these mines produced about three-fourths of the Fluorite mined in the United States.
The word fluorite is derived from the Latin root fluo, meaning "to flow" because the mineral is used to increase the fluidity of slags used in smelting flux.
Fluorite has been the state mineral of Illinois since 1965. At that time, Illinois was the largest producer of Fluorite in the United States, but the last Fluorite mine in Illinois was closed in 1995
The largest documented single crystal of Fluorite was a cube 2.12 m in size and weighed approx. 16 tons.
Fluorite comes in a wide range of colors and has subsequently been dubbed "the most colorful mineral in the world". The most common colors are purple, blue, green, yellow, or colorless. Less common are pink, red, white, brown, black, and nearly every shade in between. Color zoning or banding is commonly present. The color of the fluorite is determined by factors including impurities, exposure to radiation, and the size of the color centers.
Wonderful contrasts of honey colored Fluorite cubes with teal colored zoning and complimenting light golden Calcite crystals. In very good condition.