DALLAS, TX.- A cluster of midnight-black Manganite crystals, from Germany's Harz Mountains, sold for $149,000 to lead Heritage Auctions' $1.3 million Nature & Science Signature Auction. More than 200 lots changed hands as multiple bidders pushed prices for exemplary varieties past high estimates at the May 4 auction in Dallas.

"This category continues to attract new clients — both bidders and consignors — who are looking at fine minerals as fine art," said Jim Walker, Director of Fine Minerals at Heritage. "As expected, demand was strongest for the most unusual and top specimens but we are pleased at the bidder's response across the board."

An impressive specimen of Dioptase, covered in stout, yet highly fractal crystals in a shimmering dark green hue sold for $93,750. A yellow-green batch of pronounced, glassy crystals of Brazilianite, prized as one of the few undamaged crystal clusters known to exist, hammered for $81,250. A rare grouping of dramatic Amethyst crystals on matrix, the largest fully five inches long, saw interest from seven bidders before ending at $81,250.

Additional highlights include a bright yellow Sulfur on Anhydrite specimen, the only such mineral combination discovered amid 25+ million tons of Pyrite mined over 20 years in Tuscany, Italy, sold for $53,125, and another example of Dioptase, this one coated with a secondary layer of druzy crystals, took $46,875.

The bulk of the selection was devoted to the third offering of The Hoppel Collection, the world's largest and most valuable fine mineral collections ever offered at auction. Well-known in collecting circles for its dramatic, colorful specimens, the collection offered a rare specimen of Sphalerite on matrix, completely pristine, which more than doubled its estimate to end at $43,750. Despite being one of the most common ore minerals available, this example offered collectors a rarely seen crystal in transparent, root beer color.

Additional highlights include, but are not limited to:

Aquamarine, Chumar Bakhoor, Hunza Valley, Gilgit District, Gilgit-Baltistan (Northern Areas), Pakistan: $37,500.

Calcite, Elmwood Mine, Carthage, Central Tennessee Ba-F-Pb-Zn District, Smith Co., Tennessee, USA: $27,500.

Gypsum var. Selenite, Niccioleta Mine, Massa Marittima, Grosseto Province, Tuscany, Italy: $25,000.

Emerald. Peña Blanca Mine, Mun. de San Pablo de Borbur, Vasquez-Yacopí Mining District, Boyacá Department, Colombia: $23,750.