A cube of purple fluorite featuring accents of Barite, Sphalerite and Calcite will lead the second half of the Hoppel Fine Mineral Collection sale at Heritage Auctions on October 19-20.
The giant mineral deposit, measuring 10.5 x 9.75 x 6 inches, is expected to fetch over $200,000 when it comes up for auction. It was discovered in the Elmwood mine in Carthage, Tennessee.
James Walker, nature and science director at Heritage, commented: "The spring opener was just a taste of the treasures in the Hoppel Collection.
"This round presents the very best examples of common minerals as well as rarities you'd only ever see in museums or in the very best private collections around the world. The Fluorite is a world class, drop-dead gorgeous specimen and many of the specimens should go on exhibit in a museum."
Also featuring in the sale is a large spray of golden legrandite with an estimate of $150,000.
It was discovered in Ouejela mine, Mexico and featured a spray of golden blades radiating from a base of limonite - a characteristic common of specimens from Ouejela.
A sulphur deposit from Sicily is another highlight, displaying a large yellow dipyramidil form on top of a matrix of calconite or aragonite specked with bitumen.
The previous part of the auction in June of this year saw $4m in sales and the sale of a chunk of extremely rare rose quartz for $662,500.
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