DALLAS, TX.- A breathtaking crystalline specimen from an important American locality that recently closed down will be among the top attractions in Heritage's Fine Minerals Signature® Auction October 18.

A Rhodochrosite from Colorado's Sweet Home Mineis a stunning example of the beautiful crystals and color found in the famous locality. This example came from the "Wall Pocket" of the Sweet Home Mine, most of which has been reconstructed and put on display in the Denver Museum of Nature and Science. It features stunning color and features a massive primary crystal measuring 3.31 inches (8.4 cm) in length that sits atop a Tetrahedrite matrix.

"The appeal of this specimen extends far beyond the extraordinary eye appeal, because its origin is as important as its stunning visual beauty," says Nic Valenzuela, Director of Fine Minerals at Heritage Auctions. "The Sweet Home Mine has produced many of the world's top rhodochrosite specimens, including the ‘Alma King' that is widely considered the world's finest specimen, which, along with the reconstructed ‘Crystal Wall' now resides in the Denver Museum of Nature and Science, which is home to one of the finest museum mineral collections. The closing of the Sweet Home Mine, and now the Detroit City Portal, means that access to the vein that produced some of the most incredible Rhodochrosites is completely gone."

Another stunner in the auction is a gem-quality Tanzanite from the Merelani Hills in the Manyara Region of Tanzania. Tanzanite is well known for its otherworldly pleochroism, a phenomenon in which the color of the crystal shifts when viewed in polarized light, depending on which axis the light is being shone through. The "gem clarity" of this crystal, which measures 1.46 inches (3.7 cm) long, makes the pleochroism obvious, shifting from deep cobalt to violet and even sea green on the A-axis. It is a wonder that this crystal never was cut into a gemstone, because the transparency is unparalleled.

A Tourmaline from Brazil's Sapo Mine is a fabulous specimen from the 1998 excavation that yielded magnificent specimens from two significant pockets, the first of which produced immense, high-quality clusters of Indicolite, as well as very large single crystals. Signature to this pocket, this spectacular, richly colored crystal, which measures 5.16 inches (13.1 cm) long, is transparent and grades between zones of light blue to deep cerulean — a hue that is only enhanced when viewed with backlighting.

One of the most eye-catching treasures in the auction is a Stibnite "Sword" from the Wuning Mine in Jiujiang, Jiangxi, China that is superlative in size — it measures 17.09 inches (43.4 cm) long — and earns its moniker because of its perfectly terminated crystal that is detailed with a small spray at the bottom and crossed by two smaller Stibnite crystals that make it resemble a sword. The comparison is only increased by the bright, steely grey color and strong metallic luster of this magnificent specimen from the Brent J. McCormack collection.Also from the McCormack collection is a gorgeous Garnet from the Merelani Hills in the Lelatema Mountains of Manyara Region of Tanzania. This beauty is highly prized for its stunning green hues and transparent crystals; Tsavorites in good quality are considered to be the rarest varieties of Grossular. The Merelani Hills, where this specimen was found, comes from one of just two locations in the world with substantial finds of Tsavorite garnet.

An Azurite from the Sepon Mine in the Savannakhet Province in Laos is a magnificent crystallized piece from a choice locality for this prized mineral. Presented on a thin matrix, this piece showcases a field of substantial, deep blue, botryoidal Azurite that is complemented with a glittering microcrystalline surface.

Other top lots in the auction include, but are not limited to:

• A Quartz var. Citrine from the Cruzeiro mine in São José da Safira, Brazil

• A Tourmaline from the Sapo Mine in Minas Gerais, Brazil

• A Calcite on Amethyst from Artigas, Uruguay

• A Dioptase on Shattuckite from the Kunene Region in Namibia

• Native Copper from the Keweenaw Peninsula in Michigan

• Native Gold from El Dorado County, California