Professional Jeweler Archive: Professional Jeweler's Gem of the Year: Quartz

January 2005

Merchandise / Gemstones


Professional Jeweler's Gem of the Year: Quartz

These versatile gemstones are ideal for women who buy jewelry for themselves

by Robert Weldon, G.G.


Earth produces a copious array of quartz, but gems from this family are anything but humble despite the quantity. Quartz is beautiful, versatile and, in some varieties, utterly rare.

Because of its widespread availability, quartz is often treated casually, described by many sellers as semiprecious. For shame! This dubious designation has long annoyed gemologists, who prefer that all gems be called precious. The goal of this article is to convince you, gentle reader, never to utter the term semiprecious again.

“Quartz comes in such good colors – just think of amethyst, citrine and rose quartz,” says Michele Dempsey, fine jewelry buyer for Borsheim’s, Omaha, NE. “Amethyst beads, for example, are great first-time purchases for younger women. Unusual pieces and carved amethyst in jewelry attract older, established women. And purple is so appealing to a wide range of customers.”
For its long history and durability, its interesting varieties and new finds, its fashionable colors and affordability and its popularity among gem cutters and carvers, quartz is Professional Jeweler’s 2005 Gemstone of the Year.

Amethyst

This popular gem, which ranges from pale lavender to deep reddish purple, is the most well-known member of the quartz family. It’s been carved into beads and worn since at least the 12th Egyptian dynasty, which began in 1991 B.C. Because amethyst is the birthstone for February, it’s often the first gem a young consumer owns. It also appears often in Mother’s rings.

Today, fine-quality natural amethyst is increasingly rare. “Few people acknowledge top-quality amethyst is really rare,” says gem dealer Simon Watt of Mayer & Watt, Maysville, KY. “When I find a really nice amethyst, I hold it in as high esteem as I do a fine sapphire.”

The same is true for Mike Romanella of Commercial Mining Co., Scottsdale, AZ, exclusive distributor of amethyst from the Four Peaks Mine near Phoenix, AZ. “There’s an endless supply of 1- to 2-ct. good-quality material,” he says. “But top-grade amethyst in popular 3- to 5-ct. sizes is just 0.1% of the mine’s production. Of that rough material, some 3% is recovered in fine-quality large gems. It’s an insanely small proportion.”

Pink gems have been popular the past two years (part of a consumer product binge in pink), and now trendwatchers predict growing interest in stronger colors such as fuchsia, burgundy and purple. Accordingly, prices for these colors of gems are edging higher for top qualities.

Be aware there is much synthetic amethyst in the market. If the color is rich and the price is low, it’s likely synthetic. Top qualities of natural amethyst range from $25 to over $100 retail (see prices for various quartzes on page 64).

Ramiro Rivero of Minerales y Metales del Oriente in Bolivia, who owns the world’s only commercial mine for ametrine quartz, says it’s critical for retailers to know their suppliers well. Retailers should randomly spot-check natural amethyst lots at a qualified lab to ensure there are no synthetics.

Ametrine

This gem, a natural form of amethyst and citrine combined, is a truly rare stone, given its single source (noted in the preceding paragraph) and its unique color combination. Recent marketing changes at the source promote ametrine as a gem with mixed colors in addition to the classic bicolor split for which it’s best-known (for more information on this variety, see Professional Jeweler, June 2004, page 45, or visit www.profressionaljeweler.com and search for ametrine).

Citrine & Smoky Quartz

Citrine, which ranges from bright yellow to deep orange, doesn’t have the same rich history as amethyst, though evidence suggests pre-Colombian Incas in South America used it to some extent. Most of what’s available today results from heat-treating pale amethyst to turn it various shades of yellow and orange, though some natural citrine is mined in Brazil, Western Africa and Bolivia. Evidence of heat-treatment is difficult to determine if the citrine is relatively free of inclusions.

Few people send citrine to labs to check for treatment because the gem price is too low to merit the cost of certificates. That’s why, unless stated otherwise in writing, all commercial citrine should be considered heat-treated. This treatment is so commonplace with quartz that consumers largely accept it.

Smoky quartz is pale to deep brown. It’s quite common on every continent and is often irradiated to intensify the brown. It’s sometimes called cairngorm for the Cairngorm Mountain in Scotland, where much of it was mined and set in jewelry during Victorian times.

Citrine and smoky quartz remain popular, often returning to fashion in late summer and fall when their colors match the falling leaves. Both generally are less expensive than topaz and spessartite garnet, two other yellow to orange gems.

Lesser-Known & One-of-a-Kind Gems

The profile of lesser-known quartz varieties – such as rose quartz, rutilated quartz (containing rutile inclusions) and tourmalinated quartz (containing tourmaline inclusions) – is on the rise also. Top gem cutters have taken this to heart – and to the bank. For their part, jewelry designers often spend years searching for a certain kind of quartz or one with a certain color or inclusion pattern to fully complete their design ideas.

Phenomenal quartz, including asteriated rose quartz and cat’s-eye quartz, are popular collector stones. A new find of asteriated rose quartz in Minas Gerais, Brazil, is supplying steady quantities, says Bill Heher of Rare Earth Mining Co., Trumbull, CT. “Rose quartz is fairly common, but material that can be cut into asteriated gems and still be rich pink is quite rare,” he says. “This new material has very straight and sharp six-ray stars.” These varieties are rarely treated or enhanced.

Heher, as well as dealer Tom Cushman of Allerton Cushman, Sun Valley ID, say included quartz such as rutilated quartz are always sought after, particularly if golden rutile inclusions form patterns such as stars (following the hexagonal growth pattern of quartz).

Cushman adds that Madagascar has joined Brazil as a source of varied quartzes. The inclusions are generally of other minerals, such as garnet, tourmaline, hematite and rutile. If the inclusions form an interesting pattern, designers avidly buy them to design one-of-a-kind jewels.

All photos by Robert Weldon.

Amethyst and citrine are among classic varieties of quartz. These gems come from a new source in Namibia. Dealer Bill Barker rates them as some of the best colors he’s ever seen. Courtesy of Bill Barker & Co., Scottsdale, AZ.
Ametrine, rough and cut, from Bolivia. Courtesy of Minerales y Metales del Oriente, Santa Cruz, Bolivia.
At its best, rose quartz is semitransparent to transparent, is pronouncedly pink and has a magnificent six-ray star.
Rock crystal quartz with a six-ray rutile star is highly collectible. Courtesy of Rare Earth Mining Co., Trumbull, CT.
“Snowflakes” of manganese oxide needles appear to fall through this quartz. The white covering is microscopic fluid inclusions and mica platelets. Information courtesy of John Koivula. Gem courtesy of Allerton Cushman, Sun Valley, ID.
U.S. gem carver Sherris Cottier Shank, Southfield, MI, typifies artists who enjoy working with quartz because of its considerable size, clean crystals, color and optical qualities. This ametrine weighs 90.04 carats.

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