In our newsletter this month:

   Understanding Gem Treatments
   New in Gems
   Staff Selections
   Gemstones Worth Knowing
   Customer Questions

Rough Sapphire from Madagascar

If you're new to buying colored gemstones, one of the first things you'll learn is that many gems have been treated or enhanced in some way -- heated or fracture-filled or irradiated or dyed, to mention just some of the common treatments. This leads many buyers to wonder, Should I buy a treated stone? Or should I spend more and get a truly natural gem? This month we begin a series of articles on understanding gem treatments.

Here is one answer to the question. Gemstones are a wondrous product of nature, and their natural beauty should not be enhanced or improved in any way. If you don't care about buying a truly natural product, you can buy a synthetic or a treated gemstone. But only nature can produce a true ruby or sapphire or emerald.

Many gemstone buyers would endorse this point of view. But it is actually quite naive. After all, you don't see many people wearing unprocessed minerals on their fingers or around their necks. We expect that natural minerals will be improved by skillful cutting and polishing. Gems don't come out of the ground with a facet cut! If you've seen rough uncut sapphire (see the photo above for an example) you were probably amazed that a brilliant blue sapphire could be produced from that clump of dull aluminum oxide crystals.

So as we think about this, we realize that gemstones are a product of human craft worked on natural materials. The question then, is what kinds of enhancements are acceptable? And how do these enhancements affect the price and value of a gemstone?

One common misconception is that only inexpensive gems are treated. But in fact many valuable gem varieties are routinely treated. Tanzanite, for example, is an increasingly rare and expensive gem. But essentially all the tanzanite in the market is heat treated, since untreated tanzanite is typically brown, not blue-violet. The situation with emerald is similar -- even very expensive emeralds are oiled to fill fractures which are characteristic of the raw material. Many relatively inexpensive gem varieties, on the other hand, are rarely, if ever, treated. Garnet, amethyst, peridot, fire opal, fluorite, iolite, moonstone, quartz and prehnite are just some of the many gemstones which are almost always untreated.

There are two main reasons that gemstones are treated. In the case of some gems, the treatment is essential to the gemstone's character as we know it. Blue topaz, for example, would not exist at all in the market without irradiation treatment, since naturally occurring blue topaz is virtually nonexistent. Similarly, the characteristic ring patterns of many agates would not be so striking unless these gems were dyed using methods first discovered in ancient Rome.

The other reason that gems are treated is to improve their color and clarity. In the case of a gem like emerald, the raw material tends to be quite included and fractured, and filling the fractures with oil or resin greatly improves the appearance of the gem. Thus fracture-filling has become a standard treatment for nearly all emeralds. In the case of ruby and sapphire, untreated stones of good color and clarity do exist, but they are increasingly rare and expensive. So heat treatment is used to improves the color and clarity of lesser quality material

The value of a ruby or sapphire enhanced by heating is, not surprisingly, lower than that of an unenhanced specimen with the same color and clarity. The unenhanced gem, of course, is extremely rare. Without the enhancements produced by heating, the supply of eye-clean ruby and sapphire of good color would be so small that these gems would be available only to a tiny number of well-heeled customers. So gem treatments are a way of dealing with market realities -- the fact that the supply is scarce and demand is high.

Next month we'll look at heat treatment in more detail: how and why it works, how it can be detected, and how it affects the integrity and stability of a gemstone.

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:

• Morganite from Afghanistan: Morganite is the pink variety of beryl, belonging to the same family as emerald. It's quite hard to find, but a very lovely gem. We've found a small number of pieces in very good color, in weights from 1 to 2.5 carats.
  
  
• Peridot from Burma and China: We've expanded our excellent selection of peridot with some excellent new pieces. Our new acquisitions include some interesting pairs and lots in addition to our many larger single pieces.
  
  
• Aquamarine from Mozambique: We have just bought 3 pieces of the finest aquamarine we have ever had the pleasure to own. These have very strong color, top clarity, and remarkable size -- 2 pieces are in the 6 carat size and another is nearly 12 carats! If you have ever wanted to own a really special aquamarine, these are for you.
  
  
• Ametrine from Bolivia: We've added many new pieces to our growing collection of this popular violet golden gem. Our latest additions are mainly in the 2 to 6 carat range, in a nice selection of shapes. These are very attractive pieces at a very affordable price.
  
  
• Cornflower Blue Sapphire from Sri Lanka and Africa: We've been buying some outstanding blue sapphire recently, in the finest cornflower blue. A nice range of pieces, with weights up to 3.35 carats, with some terrific matching pairs as well. We don't think sapphire of this quality will be available at these prices for long, so we are buying them as often as we can find them.
  
  
• Tsavorite Garnet from Tanzania: Some excellent tsavorite from Tanzania has come on the market recently, with top color and clarity. One of our best buys were some wonderful matched pairs in cushion cut. If you've always wanted tsavorite earrings, here is your chance to create a really stunning pair.
  
  
• Spinel from Burma and Tanzania: We've recently found some of the finest spinel we have ever offered at GemSelect. We've bought a wonderful range of really outstanding colors, especially red, violet, blue and pink. There are some very well cut pieces in larger sizes (2-4 carats), as well as some first rate matched pairs.
  
  
• Tourmaline from Mozambique and Nigeria: We are very active buyers of tourmaline and we add new pieces to our collection every week. We now have over 300 pieces of tourmaline in stock, in a huge variety of colors, shapes and sizes.
  
  
• Apatite from Madagascar: We've just bought some new stock in this hard-to-find gem, including some lovely light green to forest green pieces that we haven't stocked before. A variety of shapes are available, in weights up to about 3.5 carats, including some matched pairs and lots.
  
  
• Lapis Lazuli from Afghanistan: This week we found some outstanding lapis lazuli in the richest of royal blue. Here's your chance to own a really fine specimen of one of the most traditional of gem materials.
  
  
• Sphene from Sri Lanka: We have added some new pieces to our stock of this rare gemstone famous for its remarkable dispersion. These are bright yellowish-green pieces in interesting shapes and cuts, mainly in the 2 to 3 carat size.
  
  
• Amethyst from Brazil: We've been finding some very good buys in Brazilian amethyst recently, including some excellent matching pairs in larger sizes (up to 9 carats per pair). We also have a nice selection of cabochons in addition to our many faceted pieces.
  
  

Each month our staff selects some of their favorite gemstones from our inventory. This month we feature some rare and unusual large pieces from our recent acquisitions. Click on the photos to go to the detail pages.

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

Andalusite is a strongly pleiochroic gem, which means that it displays different colors when viewed from different directions. While it is a strikingly beautiful gem, it is largely unknown by the gem buying public. With a hardness of 7-7.5 on the Mohs scale, it is very suitable for all kinds of jewelry.

Its trichroic nature, which shows shades of brown, green and reddish brown depending on the orientation of the crystal, can be enhanced by specific orientation and cut. Those cuts with a long axis such as an oval, marquis or emerald cut tend to show one color near the center and a second, usually darker color near the ends. Square and round cuts usually blend the colors into a mosaic. Most specimens contain some inclusions, the most common being rutile needles. Brazil is the chief producer, but Sri Lanka, Russia, Spain and the US also have deposits.

For more information see our Andalusite Info Page.

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.

A final note -- If you send us email, please be assured that we answer all our email very promptly, 6 days a week. But we sometimes have problems with spam filters on the receiving end, so please adjust the settings on your mail client so you can receive mail from help@gemselect.com.

Happy gem hunting!

Your friends at GemSelect