Spectacular Gemstone Collection Sold

More than 200 lots of what was promoted as the finest-quality colored gemstones ever offered at unreserved public auction were presented at Shreve’s Auction Galleries in New York in May. The auction of what was billed as the “Connoisseur’s Gem Collection” offered the private collection of Dennis Dunn, the fruit of Dunn’s 15-year quest to gather the finest colored gems available. All gems in the auction were certified as completely natural.

The list of gemstones was impressive, leading with a 78.59-ct. “Empress of Alma” Sweet Home mine rhodocrosite, reportedly the third-largest faceted rhodocrosite in the world (the red gem pictured at left). The stone sold for $12,000.

Among the other important gems were a 29.93-ct. cushion-cut tanzanite, which sold for $11,000; an 8.91-ct. “imperial pink” topaz, which fetched $10,500; and a 15.88-ct. indicolite tourmaline, hammered at $9,000.

The auction’s finale featured a gem sculpture by Thomas McFee, an 11-in.-tall bronze statue depicting a mythical Aztec princess holding a Mexican opal mask of Montezuma. It sold for $7,500.

Above left: This incredible 29.93-ct. cushion-cut tanzanite sold at auction for $370 per carat.

Above right: This 78.59-ct. rhodocrosite, mined from the famous Sweet Home mine in Alma, Colo., sold at auction for $150 per carat.

Left: A bid of $7,500 took “The Aztec Princess” by award-winning North American gem artist Thomas McFee, the last item on the block at Shreve’s Auction Galleries in New York. The princess is constructed of 22k gilded bronze. She wears a headdress of rhodonite, lapis, malachite, B.C. jade, chrysoprase, and mauve agate and offers a carved Mexican opal mask of Montezuma.

Looking for Benitoite

AZCO Mining Inc. has secured an extension until Jan. 1 on its option to acquire the benitoite gem mine in San Benito County, Calif. AZCO paid the owners of the mine $20,000 to acquire the extension. The original agreement set the purchase price at $1.5 million.

Benitoite, the California state gem since 1985, is most notably blue. It’s known for its sapphire-like color and luster and for its diamond-like dispersion. The price of the faceted stones is comparable with that of fine sapphires and tanzanites. The average wholesale price for benitoite is currently about $1,000 a carat. Discovered in 1907, the mine is acknowledged to be the only source of gem-quality benitoite in the world.

The beautiful sapphire-blue gem, found only in Northern California’s San Benito County, may be more readily available if extended exploration by AZCO Mining Corp. proves profitable.

Montana Sapphire: The Queen Gem of America

All the big three colored gems—emerald, ruby, and sapphire—are found in North America, but only sapphire exists in great enough quantity to attain commercial significance. And nearly all of it comes from Montana.

Montana sapphires occur in four areas, all in the west near Helena, the state capital. Discovered in 1865 by prospectors looking for gold, the first blue sapphire pebbles turned up amid the gravel along the Missouri River. The sapphires were largely ignored until the 1890s.

Yogo Gulch. Any discussion of Montana sapphire begins with Yogo, famous for its natural saturated “steely” and “cornflower” blue colors as well as more unusual purples and violets. Yogo Creek (now called Yogo Gulch) sapphires became popular just before the turn of the century, about the same time the Kashmir cornflower blue sapphires from Asia were making their way into the European market.

Yogos became famous following their appearance at the Paris Exposition of 1900. Tiffany & Co., guided by gemologist George Kunz, had been purchasing Yogos from the local miners, using these sapphires for the company’s exclusive high-end jewelry designs. British gem wholesalers, also interested in the American sapphires, bought the Yogo mine and sent all of the gem-quality material to their Sri Lankan cutting factories. From there, the smaller gems went to Switzerland for use in Swiss timepieces. The larger gems were used for jewelry seen commonly among members of British royalty and American high society.

Yogo quality is quite spectacular. The gems contain few visible inclusions or color zoning. The only hitch is that the gems are small, usually less than a carat; stones larger than 2 cts. are rare. Color is typically steel-gray blue for the smaller stones and cornflower blue for 1-ct. stones and larger.

Today, there are two separate claims along the gulch. Production on one claim is limited to exploratory mining by Cascade Mining Co. and individual mining by Roncor, owned and operated by Jeff Kunisaki. On another claim, just a stone’s throw away, Vortex Mining Corp. is recovering the Yogos as well. Even with both claims producing sapphire rough, there’s only limited faceting material.

But there’s no shortage of requests for the natural-color sapphires. Kunisaki reports that every size and shape is on order, but supply can’t keep up with demand. As a North American gem, its rarity in both natural fine color and clarity makes the Yogo sapphire a collector’s gem.

Missouri River. The headwaters of the Missouri River flow north past Helena and up toward Great Falls. It’s here, just north of Helena at the Eldorado claim, along with other smaller claims, where the Missouri sapphire gravels have been recovered. Stones found at the river are typically colored pink, pale red, purple, yellow, and orange. They respond well to heat treatment for color enhancement. Pale blue or blue-green is quite rare, as is deep blue. The commercial river deposits currently are inactive.

Rock Creek. Going west from Helena you encounter Gem Mountain and the Rock Creek mining areas. From here, recovered sapphires show a full spectrum of colors, including many bicolor sapphire crystals. The Rock Creek sapphires are very similar to those from the Missouri River.

Dry Cottonwood Creek. For decades, Dry Cottonwood Creek has been producing larger yellow, gold-and-green, pink, and blue sapphire crystals. But in recent years, American Gem Corp., the owner of the claim, has had to give up the property to reduce its debt. No longer mining, American Gem has no need for the property. High mining and land reclamation costs have diminished the value of the property.

Formed in 1991, American Gem Corp. is known not only for its fabulous array of multicolored sapphires but also for its constant business restructuring. Its new management says the company maintains “one of the world’s largest holdings of high-quality cut and rough sapphires in the world.” With more than 300,000 carats of blue, green, yellow, orange, pink, and purple faceted goods along with a substantial inventory of rough, that’s a genuine claim.

Canadian investment banker Vic Alboini, the new president and CEO of American Gem Corp., has taken some bold steps to make American Gem profitable. “American Gem is no longer a mining company,” says Alboini. “American Gem is a marketing company with its primary focus to develop Internet e-commerce businesses.” In other words, it needs to sell sapphire. The company intends to market heavily through its Internet site,

American Gem Corp. also will maintain a profitable “fee-dig” business at the Rock Creek mine site west of Philipsburg, below Mount Gem. Tourist traffic is lucrative. The daily fee for digging sapphire is $50, with picks and shovels provided. For those who don’t want to dig, $10 gets you a 25-lb. bag of already-mined gem gravel to sift through. If you find a gem in the bag—and chances are good that you will—you can have it heat-treated for $5 and then faceted for an additional $25.

Deer Lodge County. Tom Lee’s Gem River Mining Corp. has operations in Deer Lodge County. Like most Montana sapphire, the material mined in Deer Lodge County generally is small. But on rare occasions, Lee claims, “I’m actually netting polished goods up to 8 cts.!” Commonly found colors include blue, green, teal, yellow, orange, white, and pink. There’s also some true ruby. Most, if not all, of the material is enhanced by heat.