DALLAS, TX.- A monumental purple cube of Fluorite accented by crystals of Baryte, Sphalerite, and Calcite — a rare discovery from the Elmwood Mine near Carthage, Tenn. — is expected to sell for $200,000+ as Part II of the record-setting Hoppel Collection, returns Oct. 19-20 at Heritage Auctions. Headlining the 519-lot Nature & Science Signature® Auction, the Hoppel Collection set the mineral world on fire and claimed several records following its nearly $4 million June debut.

"The spring opener was just a taste of the treasures in the Hoppel Collection," said James Walker, Director of Nature & Science at Heritage. "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."

Leading the top examples is a large and rare spray of golden Legrandite discovered in Durango, Mexico, which is expected to sell for $150,000+. An enormous bright yellow Sicilian Sulfur crystal expected to bring $80,000+. A near gemstone-quality example of cobalt blue Azurite surrounded by rust orange Pyrite and Sulfides may bring $25,000+. Brilliantly reflective crystal faces of Hematite encased in Andradite Garnet and Calcite are expected to bring $20,000+.

The auction holds specimens from every continent (except Antarctica) including a Tourmaline displaying colorful sprays of blue and pink crystals towering 13 inches tall, which is expected to fetch $55,000+. A gem-quality Aquamarine tipping in at an astounding 5,021.5 carats, is expected to sell for $35,000+ and a seldom seen but very fine Imperial Topaz gemstone from the Southeast Region of Brazil, is expected to bring $32,000+.

A particularly large specimen of dark orange Scheelite pyramids, discovered in a remote mountain district near the heart of a Chinese panda preserve, and surrounded by a complex field of bladed Muscovite Mica crystals may bring $15,000+. A dazzling example of sparkling green Dioptase on Calcite may sell for $15,000+.

Like twigs beneath a coating of winter ice, an unusual transparent layer of Fluorite covering silvery prisms of Stibnite may cross the block for $12,000+ and a striking green specimen of Pyromorphite may fetch $12,000+. A stunning example of double-peaked Calcite crystals jutting from a sea of rust red microcrystals from China's famed Leiping Mine may bring $10,000+.

The event also features a non-floor session presenting of more than 100 high-quality specimens and "a few sleepers we through in just to make sure people are paying attention," Walker said.

The auction also presents a world-class selection of fossils, led by a rare, one-of-a-kind plate displaying the remains of a Permian Period (299 to 251 million years old) amphibian that choked to death on its prey. It is believed to be the only specimen of an "amphibian aspiration" known to exist and as such it is already generating early auction buzz and may cross the block for $150,000+.

Additional lots include an extremely large Canadian Gem Ammonite, which may sell for $60,000+, and a rare and pristine Elephant Bird Egg — virtually unheard of on the natural history market — which could change hands for as much as $50,000+.