This month's newsletter is all about one of our favorite gemstones, tourmaline:

   How Tourmaline Led the Modern Colored Stone Market
   New in Gems
   Staff Selections
   Gemstones Worth Knowing
   Customer Questions

Back in 1875, a 20 year old American mineral collector named George Kunz walked into the offices of Tiffany & Co. in New York City with some fine green tourmaline he had obtained from the Mount Mica mine in Maine. Tiffany & Co., founded in 1837, had already become the largest jewelry business in the world, but their business was strictly in precious stones -- diamond, ruby, emerald and sapphire. Kunz wanted to sell them on semi-precious stones, and he brought a green tourmaline to do it.

Kunz managed to get in to see Charles Tiffany on that day, and convinced Tiffany to buy the tourmaline. It was the beginning of a long relationship. Kunz eventually became the resident gem expert at Tiffany, an influential position that he held for nearly his whole life.

Tiffany became the world leader in colored gemstones and introduced many new colored gem varieties to the market in their famous jewelery designs. But it is fitting that Tiffany's leadership in the colored stone market began with that tourmaline they purchased from George Kunz.

That's because tourmaline is in many respects the quintessential colored gemstone. It combines good hardness (7 to 7.5 on the Mohs scale) with excellent durability (it has no cleavage). It occurs in an astonishing array of colors, including bi-color and tri-color crystals such as the distinctive watermelon variety, that are instantly recognizable as tourmaline. The best tourmaline has excellent clarity and a vitreous luster that makes it the equal of any of the precious stones. And because of its tremendous color variation and pleochroism, nearly every piece of tourmaline is quite unique.

Tourmaline also has some intriguing physical properties that make it a rather special mineral. If a tourmaline crystal is heated and then cooled, or had pressure applied (e.g, by rubbing), it will become electrically charged. It will then attract dust particles as well as small pieces of paper. These effects, known as pyro-electricity and piezo-electricty, require tourmaline to be cleaned more often than other gemstones.

Tourmaline is found in many places in the world. But it is one of the few gemstones for which the USA is famous. The first American discoveries were made in 1822 in the state of Maine. California became a large producer of tourmaline in the early 1900's. The Maine deposits tend to produce crystals in raspberry pink-red as well as minty greens. The California deposits are known for bright pinks, as well as interesting bicolors. During the early 1900's, Maine and California were the worlds largest producers of gem tourmalines. The Empress Dowager Tz'u Hsi, the last Empress of China, loved pink tourmaline and bought large quantities for gemstones and carvings from the then new Himalaya Mine, located in San Diego County, California. Today most of our tourmaline supply comes Africa, particularly Nigeria and Tanzania,

Our buyers are in the market every day finding the best values for our customers. Here are some of the excellent buys we've made in the last few weeks:

• Cornflower Blue Sapphire from Madagascar: We've finally found some more of the very popular round blue sapphires from Madagascar. Good color and quite clean; most of the stock is VS-grade. In sizes from about 0.5 carts to 1.3 carats. These make outstanding earrings.
  
  
• Chrome Diopside from Russia: We have acquired a small number of pieces of rare chrome diopside from Russia. This is a vivid green diopside, colored by trace amounts of chromium. We find these only about once a year.
  
  
• Red Pink Tourmaline Cabochons from Nigeria: We've just acquired some very fine red pink tourmaline cabochons. Terrific color saturation and very good luster. Quite clean for cabochon-grade material.
  
  
• Rutile Quartz from Brazil: Rutile quartz is transparent quartz with inclusions of golden rutile crystals in delicate patterns. Every piece is entirely unique. A favorite with collectors. Sorry only a small stock in these.
  
  
• Andalusite from Brazil: Andalusite is a fascinating gemstone with distinctive pleochroic qualities, meaning it has different colors when viewed from different directions. It's quite a hard gemstone (7 to 7.5 on the Mohs scale) so it's suitable for all kinds of jewelry.
  
  
• Red Spinel from Burma: We think all spinel is wonderful stuff, but the red is especially valuable. We've been adding a number of very interesting pieces to our stock. You'll find red and deep red spinel in oval, octagon, cushion and trillion shapes, in sizes ranging from about 1 to 3 carats. Red spinel is an excellent substitute for ruby, and in fact has some characteristics that are superior to ruby. In case you missed it, we had a good article on the topic in our December 2006 Newsletter.
  
  
• Moonstone from India: There is nothing quite like the delicate shimmer of light that is so distinctive of moonstone. We've just bought a new stock of some first-rate pieces, with colors ranging from smoke gray to mocha to orange. These are good sized pieces, mainly in the 10 to 25 carat range. They make outstanding jewelery and are very popular with collectors. We also have some interesting new Star Moonstone as well.
  
  
• Lapis Lazuli from Afghanistan: Lapis lazuli is one of the most historically important of all decorative minerals. It's not so easy to find these days, but we were lucky and picked up a good stock of some lovely specimens. Collectors take note!
  
  
• Chrome Tourmaline from Tanzania: One of the rarest and most valuable variety of tourmaline, chrome tourmaline is colored by trace amounts of chromium and vanadium, giving it a remarkably vivid forest green hue, similar to fine emerald and tsavorite garnet. We rarely find these, especially in this quality.
  
  
• Cat's Eye Tourmaline from Brazil: You rarely see them, but tourmaline sometimes exhibits chatoyancy or the cat's eye effect. These lovely olive green cabochons are from Brazil. Available in some larger pieces, these make very interesting jewelry.
  
  
• Tsavorite Garnet from Kenya: Tsavorite garnet is rare and expensive, but we recently bought a small lot of rough stone which we have been cutting in our shop. Tsavorite tends to have some inclusions, but its vivid green is unique in the gems world.
  
  
• Agate from Brazil: Agate is a form of chalcedony that forms in layers, often producing distinctive multicolored bands. We've acquired a number of fascinating pieces from Brazil, in a variety of shapes, sizes and colors.
  
  
• Top Spessartite Garnet from Namibia: We've made a great buy on some very fine mandarin spessartite garnet. These are high quality pieces, mainly VVS-VS and VS, with the top mandarin orange color. In trillions, ovals, pears and octagons, in sizes 1.25 ct to around 2.5 ct.
  
  
• Red Orange Sapphire from Tanzania: We have been searching for these gorgeous red orange Songea sapphires for a while, and this week we found them. We were only able to buy a small stock in these, mainly in the 1 to 1.5 carat size.
  
  
• Pink Sapphire from Madagascar: We often have have some lots of pink sapphire in small sizes, but we rarely find pieces over a carat. We've just found a small number of pieces in 1 ct to 1.25 ct size, with excellent color saturation and good clarity. We've had so many requests for pink sapphire, so here's your chance.
  
  

Each month our staff selects some of their favorite gemstones from our inventory. This month they've chosen some special tourmaline pieces. Click on the photos to go to the detail page for the item.

Each month we focus on one of the lesser known gemstones. This month's featured stone is Chrome Tourmaline.

Tourmaline is of course a very well known gemstone family. But chrome tourmaline is not well known at all, largely because it is rare and expensive and few people have had a chance to own it.

Chrome tourmaline is not just a tourmaline color, but actually a distinct variety, called chrome dravite. It was first mined in Tanzania in the 1960's, so it is a recent discovery. Thus far it has only been found in East Africa, specifically in Tanzania, Kenya, Zambia and Namibia. Like emerald and tsavorite garnet, fine chrome tourmaline is a visually pure "forest" green with slightly yellowish to bluish secondary hues. The blue will normally show itself in incandescent light, the yellow will be more visible in daylight. A blue secondary hue, as in the photo above, is preferred to yellow.

Every month we answer questions of general interest from our customers. Please feel free to send your questions to help@gemselect.com, with "Newsletter question" in the Subject line.

This month we answer some questions about tourmaline.

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Happy gem hunting!

Your friends at GemSelect