159.5 carat 2.1" terminated gem diaspore crystal showing green to red-violet color change

Diaspore is a native aluminum oxyhydroxide, AlO(OH) which crystallized in the orthorhombic habit. It forms as a secondary mineral in weathered surface zones in clay and limestone deposits, in metamorphic marbles, and in nepheline syenite pegmatites. Massive diaspore is a major ore of the aluminum ore bauxite, but crystals are rare, and good diaspore crystals are very highly prized. There are many sources for diaspore, but few have produced good crystals. After a 10-year lapse in production in Turkey, in 2011 a new source was found in the Kucukcamlik and Buyukcamlik mines, 12 km south of Pinarcik in the Ilber mountains, which are in the Milhas-Mugla region of southeastern Turkey. The new site, which boasts several openings, has produced spectacular crystals, some of which have been cut into faceted gemstones. Gem marketers call it "Sultanate" (Sultanate) to make it sound more appealing; other trade names include "Ottamanite" and "Csarite".

The zinc mines around Carthage, Tennessee have been famous for many decades for producing superb examples of calcite, fluorite, sphalerite and barite. Very large, exceptionally sharp and sometimes gemmy calcite crystals and clusters were fairly common. These often featured sharp single and multiple terminations, and came in colors ranging from gold to orange, and sometimes sporting red-orange tips. Well-formed fluorite crystals were less common, but usually available in transparent to translucent blues and purples and all shades in between. Plates of black to brown sphalerite crystals, sometimes tined red, were customary, typically with brilliant luster. Last but not least, large hemispheres of ivory colored barite were often found perched on the sphalerite matrix pieces. The quality of these specimens had long ago established these zinc mines as an American classic locality, and exemplary specimens were often featured in displays at the big mineral shows. And then, in 2004, the mines closed and the source dried up.

On Sept. 24, 2009, Louise Jonaitis and some friends went on a field trip to Newry Hill on Plumbago Mountain in Newry, Maine. Jonaitis and her partners purchased Plumbago Mountain in 2008 and were planning to mine there for tourmaline. The day of the field trip, they had planned to bring up the bulldozer, backhoe, track drill, compressor and other heavy equipment they would need to do the mining. Before they even finished unloading the machinery, someone found a gem blue tourmaline crystal right on the surface above the very area they planned to work. Describing that day, Jonaitis later said, "The day we brought the machinery up, we ran right into it. It was sticking right out of the ground, so we dug 4 feet down and there was a pocket, and then it kept going." Careful blasting and backhoe work revealed the first of nine pockets, varying in size from 8 inches to almost three feet. The first Eureka Blue crystal weighed 111 carats. "It was kind of exciting after all this time," Jonaitis said. "We found more blue tourmaline than anyone else in the world has found."

2" Azurite with Malachite, Milpillas Mine, Cuitaca,
Mun. de Santa Cruz, Sonora, Mexico

Outstanding azurite crystals and malachite pseudomorphs from the Milpillas copper mine, 30 km NW of Cananea, in Cuitaca, Mun. de Santa Cruz, Sonora, Mexico, began appearing on the mineral market in 2006. At their best, the specimens from this new classic locale are right up there with the best crystals from Bisbee and Morenci, Arizona or Tsumeb, Namibia. Three different minerals from this mine have captivated the mineral market: electric blue azurites; velvety, dark green malachite pseudomorphs (replacements) after azurite; and brilliant green brochantite in long, slender, acicular crystals.

The tiny town of Riemvasmaak in the Kakamas district in Northern Cape Province, South Africa has become famous in recent years for the luminously transparent octahedral crystals of green fluorite collected in the region. Riemvasmaak is now considered by many as a classic locality, and arguably one of the world's greatest fluorite localities ever. Since late 2006, crystals have been brought to market featuring mainly octahedral and modified cuboctahedral habits. Besides the rich emerald green color, fluorite from this locality is found in blue, purple, orange, yellow and colorless.

1.8" Greenish yellow fluorapatite crystal with minor hematite on surface
Cerro de Mercado in Ciudad Durango, Durango, Mexico

Numerous veins containing gemmy yellow fluorapatite crystals cut through the hematite massif of Cerro de Mercado in Ciudad Durango, Durango, Mexico. The transparent crystals from this occurrence, both on and off matrix, are beautiful and sharply formed, in bright colors ranging from lemon yellow to greenish yellow. They have been collected for decades, though recent changes at the mine have made them much scarcer.