March 2008
 In our newsletter this month:
Tanzanian Zircon
New and Interesting Gemstones
New Content at GemSelect
Gemstones Worth Knowing
Customer Questions
Tanzanian Zircon
We wrote a newsletter feature on zircon two months ago and didn't expect to be writing about it again so soon. But we were so impressed by the Tanzanian zircon that has recently come on the market that we wanted to share the story of these exceptional gemstones.
 We know that many gemstone buyers are well acquainted with the attractions of zircon. We also know that some people have never heard of it, or confuse it with the diamond simulant cubic zirconia. Zircon is a zirconium silicate and is the oldest known mineral on earth. It has good hardness (6.5 to 7.5 on the Mohs scale) and it combines a very high refractive index (approaching that of diamond) with strong dispersion, the tendency to split white light into the colors of the spectrum. In short, zircon is a very brilliant gem with impressive fire.
Most of the zircon we've seen in the past comes from Cambodia, our neighbor to the east. Northwestern Cambodia produces very fine material, some of which can be heat-treated to produce the highly regarded blue zircon. But zircon in its natural state ranges in color from yellow-brown to orange and red.
The natural zircon colors have never had quite the same appeal in the market as the heat-treated blue. But we think that the impressive material recently found in Tanzania will change a lot of minds about natural zircon. The range of colors is unusual, with some stunning colors we've never seen before in zircon. And the clarity is outstanding, with virtually all the pieces VS grade or better, with more than half the stock VVS grade. But the remarkable thing is that these zircons are big as well!
 The colors include a range of oranges from golden brown to a spessartite-like mandarin. The most unusual colors are a range of rose tones, from cinammon to a pink cranberry, with some a combination of orange and rose hues. There are a few quite rare reds, from orange-red to crimson. The only heat-treated pieces in the group are some brilliant yellows; all the others are completely untreated.
There is a good selection of shapes, including ovals, rounds, pears, emerald cut and a few trillions and fancy cut pieces. Zircon is not a gem typically found in large sizes, but most of the pieces in this lot are over 2 carats. There are a good number of stones in the 5 carat size, with a few pieces as large as 6.9 carats. It is very unusual to find outstanding colors with great clarity in these large sizes.
We are buying as much of the Tanzanian zircon as we can. Right now the supply is good, but like many colored gems, one never knows how long it will last. The first signs of tightening supply is when the pieces get smaller and the clarity declines. So far we're still seeing large high quality specimens. |
| New and Interesting Gems -- updated July 16th |
 |
Pink Tourmaline from Mozambique: Pink is the most popular color in tourmaline and we have just expanded our stock with some outstanding new pieces. The shades range all the way from soft pink to hot pink and purple pink. We have more than 350 pieces in all, in a wide range of sizes and shapes. We buy pink tourmaline whenever we can find it, but rarely find this many fine pieces. |
|
| |
 |
Chrysoberyl Cat's Eye: The most famous and valuable cat's eye gemstone is chrysoberyl cat's eye. In fact when the term cat's eye is used alone in the gem trade, it always refers to chrysoberyl cat's eye. All other types of cat's eye gems require an additional varietal designation, such as cat's eye apatite. Chrysoberyl cat's eye is so highly regarded due to its excellent hardness (8.5 on the Mohs scale), superb luster and remarkably sharp cat's eye effect. We have just found some excellent pieces at an unusually good price. |
|
| |
 |
Hessonite Garnet from Madagascar: Hessonite belongs to the grossularite garnet group, which also includes tsavorite garnet. While most grossularite garnet is green, hessonite typically has a orange-brown color which has earned it the nickname cinnamon stone. We rarely find hessonite in the market, but we've just bought an excellent selection of matched pairs in a variety of shapes. |
|
| |
 |
Star Diopside from India: Diopside is a calcium magnesium silicate with a hardness of 5-6 on the Mohs scale. Diopside is best known for the vivid green chrome diopside, but the black diopside exhbiiting asterism or the star effect is rare and unusual. We've acquired a small number of pieces from India, in very impressive sizes (upt to 48 carats). Collectors take note, we hardly ever see these. |
|
| |
 |
Carnelian from India: Carnelian is a brownish red to orange variety of chalcedony quartz, colored by trace amounts of iron. Carnelian is one of the oldest known gemstones, being widely used in ancient Rome to make signet or seal rings. Most of the carnelian you'll find in the market is agate which has been dyed and heated, but we have found a very fine parcel of hard-to-find untreated natural carnelian, ideal for gem collectors. |
|
| |
 |
Rhodochrosite from Argentina: Rhodochrosite is an interesting rose-colored gemstone that was only introduced to the market around 1940. Though it is not particularly hard (about the same as fluorite) it has become popular as a decorative material due to its attractive soft color and its intriguing variegated markings. We've found a nice parcel of Argentine rhodochrosite and have a good selection of affordable cabochons in sizes up to 12 carats. |
|
| |
 |
Morganite from Afghanistan: The pink form of beryl was named Morganite, after the American banker and collector J.P. Morgan. A soft pink to violet, Morganite belongs to the same family as emerald and aquamarine. Like the other beryls, Morganite is quite hard (7.5 to 8 on the Mohs scale). We've just acquired a good range of high quality pieces, mostly in the 1.5 to 2.0 carat size. These are clean and well-cut stones with the delicate pink hue for which morganite is famous. |
|
| |
 |
Chrysoprase from Tanzania: Chrysoprase is considered the rarest and most valuable stone in the chalcedony quartz group. That's quite a distinction considering that the chalcedony species includes agate, chalcedony, onyx, carnelian, bloodstone and jasper. But chrysoprase, it is fair to say, is also the least known of all the chalcedony varieties. Chrysoprase is a vivid apple-green to deep green gem, colored by trace amounts of nickel, and makes stunning jewelry. |
|
| |
 |
Spinel from Burma: We buy fine spinel whenever we can find it, and we've recently added some very fine pieces of Burmese spinel in larger sizes. You'll find reds, violets, blues and grays in a variety of shapes, including a number of hard-to-find cushion cuts. Sizes range from 1.5 carats all the way up to 5 carats. |
|
| |
 |
Ruby-Zoisite from Tanzania: Ruby-Zoisite, also know as anyolite, is the natural combination of ruby and zoisite crystals in a single specimen. Zoisite, the same mineral as tanzanite, provides an earthy green and black color while ruby lends exciting pink and red highlights. Ruby-zoisite is usually cut en cabochon or carved. We've recently purchased some excellent cabs, but also some unusual and rarely seen faceted peices. |
|
| |
 |
Dendritic Agate from India: Dendritic agate is a whitish-gray or colorless chalcedony with fern-like inclusions known as dendrites. The inclusions look like plant material, but they are actually iron or manganese. We've found a small number of fascinating pieces from India. |
|
| |
 |
Yellow Sapphire from Thailand: We've just acquired some brilliant yellow golden and yellow orange sapphires from Thailand, mainly in sizes from 1 to 3 carats, with a few larger pieces as well. You'll find a nice range of shapes, with many pieces VS or VVS clarity. |
|
| |
 |
Ruby Cabochons from Madagascar: Recently we've found some excellent ruby cabochons from Madagascar in the 3 to 14 carat size. These are pure red and some are clean enough to be graded translucent. These cabs make wonderful jewelry and the price is very attractive as well. |
|
| |
 |
Grossularite Garnet from Kenya: Grossularite (or grossular) garnet is a calcium-aluminium garnet. The name grossular is derived from the botanical name for the gooseberry, grossularia. Grossularite garnet combines excellent brilliance and hardness. We've recently acquired some very fine pieces from Kenya, mainly in the 1 to 2 carat size. |
|
| |
 |
Fire Agate from Mexico: Agate is a type of chalcedony quartz that forms in concentric layers in a remarkable variety of colors and textures. Fire agate is an opaque, limonite-bearing chalcedony with iridescence which is created by diffraction of light by the layered structure. We've found some excellent pieces from Mexico, in sizes up to around 10 carats. |
|
| |
 |
Diaspore from Turkey: Diaspore, sometimes marketed under the name Zultanite, is a color change gem from Turkey recently introduced to the international market. Under natural or fluorescent light, Diapsore has a kiwi green color, with flashes of yellow. Diaspore displays a champagne color under incandescent lighting, and when exposed to subdued lighting, such as candlelight, has a pinkish color. We have recently added some fine matched pairs to our extensive stock of this popular gem. |
|
| |
 |
Sunstone from India: Sunstone is a type of plagioclase feldspar that exhibits a spangled appearance, due to reflections of red haematite. We've recently acquired some interresting sunstone cabochons from India, in a good range of sizes from 5 to 50 carats. |
|
| |
 |
Labradorite from Madagascar: Labradorite is a member of the plagioclase feldspar group, which also includes andesine and sunstone. Labradorite displays an iridescence in lustrous metallic tints, often blue and green. It is mainly caused by interference of light from lattice distortion. We've found some very interesting labradorite cabochons in sizes up to 10 carats. |
|
| |
 |
Scapolite from Namibia: Scapolite is a sodium calcium aluminum silicate with a hardness of 5.5 to 6 on the Mohs scale. It is named from the Greek for "stick," since its tetragonal crystals grow in columns. As a gemstone scapolite is not well known, but it can be a very attractive stone. Its color, which is usually a virbrant yellow to orange, pink or violet, is its best feature. We've found some excellent pieces in brilliant yellow and gold, in szies from 3 to 6 carats. |
|
| |
 |
Cat's Eye Apatite from Africa: Cat's eye apatite can often be confused with the more expensive chrysoberyl cat's eye, but apatite is a softer stone (5 on the Mohs scale) that is best used for pendants and earrings. It does exhibit a very striking cat's eye effect, however, and is sought after by collectors. We've recently bought some first rate pieces in both green and honey, in sizes from 2 to 6 carats. |
|
| |
 |
Spessartite Garnet from Mozambique: We have added a large number of new pieces to our extensive inventory of this very popular gem. We now have over 180 pieces in stock, in mandarin and red-orange, in both cabochon and faceted. The range of sizes and quality grades is extensive. We've just purchased a number of high grade pieces with superb brilliance, at some of the best prices we've seen in spessartite in the past year. |
|
|
|
|
New Content at GemSelect
We add hundreds of new gems to our inventory every day. But we also add new content to our site each week as well, in the form of articles and reference material.
We've recently written an article explaining gemstone cleavage, and we've put together a chart listing the cleavage properties for more than 60 varieties of gemstones.
In our growing Gemstone Articles section you'll find a number of new pieces on gemstones written by the GemSelect staff, on topics as diverse as gem appraisals and copper-bearing gems.
Gemstones Worth Knowing
Each month we focus on one of the lesser known gemstones. This month's featured stone is Beryl.
The beryl family is one of the most important gemstone families. It includes emerald, aquamarine and morganite as well as golden and red beryl. Beryl is quite a hard stone (7.5 to 8 on the Mohs scale) and suitable for all kinds of jewelry. Golden beryl, occurring in lemon-yellow and golden-yellow, tends to have exceptionally good clarity. Inclusions are rare in golden beryl, and the superb clarity combined with the fine color make this beryl an excellent stone for all kinds of jewelry. Golden beryl is found in Brazil, Madagascar, Namibia, Nigeria, Sri Lanka and Zimbabwe.
For more information see our Beryl information page
Customer Questions
Every month we answer questions of general interest from our customers. Please feel free to send your questions to help@gemselect.com. |
| Q: |
I notice that you sell red sapphire on your website. I thought red corundum is ruby while all the other colors of corundum are called sapphire. Am I right? AJB, USA |
| A: |
Yes, you're right. If it's red and it's corundum, it is almost always called ruby. There are really only a few exceptions to the rule. One exception is corundum that is red-orange or pink-red. It might be called either sapphire or ruby (it's a judgement call). The other exception is when the red color of the corundum is the result of heat treatment with beryllium. In that case it is normally called sapphire as a reference to its humbler beginnings.
|
| Q: |
I bought 2 gems from you recently, but I forgot to print out all the details on them. Now I can't find them on your website. Can you help? MD, Australia |
| A: |
When a gem is sold, we no longer show it on our website, since no one wants to shop for items that aren't available. However, the information for sold items can still be found. Just enter one or more gem ID's (separated by commas) in the search box on our home page, and it will bring up the records for those gems. The gem ID is the 5 or 6 digit number that you'll find on every detail page, where you see a line that looks like "4.52ct VVS Tourmaline (#153854)." In that case 153854 is the gem ID. We always include the gem ID's in any emails we send you about your purchase. |
|
| 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 |
|
|
WORLDWIDE DELIVERY IN JUST 3 DAYS!
.gif){kind=small}