ELECTRONIC GEMSTONE LIBRARY

SAPPHIRE- is the birthstone of September. The finest sapphires are considered to be the blue variety - specifically those from Burma and Kashmir, which are closest to the pure spectral blue. Fine, brilliant, deep blue Burmese sapphires will surely dazzle the eye and the pocketbook, as will the Kashmir, which is a fine velvety-toned deep blue. Many today tend to be too dark, how ever, because of the presence of too much black and poor cutting (cutting deep for additional weight), but the deep blues can be treated to lighten the colour. The Ceylon sapphires are a very pleasing shade of blue, but are a less deep shade than the Burmese or Kashmir, often on the pastel side. We are also seeing many Australian sapphires. These are often a dark blue, but have a slightly green undertone, as do those from Thailand, and sell for much less per carat. They offer a very afford able alternative to the Burmese, Kashmir, or Ceylon, and can still be very pleasing in their colour. Blue sapphires also come from Tanzania, Brazil, Africa, and even the U.S.A. (Montana and North Carolina). They also come in other colours, especially yellow and pink, and in smaller sizes some beautiful shades of green. These are known as fancy sapphires. Compared to the cost of blue sapphire and ruby, these stones offer excellent value and real beauty. Techniques have been developed to treat natural sapphires to remove a certain type of flaw (needle type) and to change the colour for example, to create a "Ceylon" sapphire that never came from Ceylon (Sri Lanka) but whose colour looks like that of a Ceylon.

TANZANITE - a variety of the mineral zoisite was not considered a gem material until 1967, when a beautiful, rich, blue to purple blue, transparent variety was found in Tanzania (hence tanzanite). Tanzanite can possess a rich, sapphire blue colour (possibly with some violet red or greenish yellow flashes). This lovely gem can cost over $2,000 per carat today in larger sizes. But one must be cautious. It is relatively soft, so we do not recommend tanzanite for rings (unless it's set in a very protected setting) or for everyday wear in which it would be exposed to knocks and other abuse. One must also be aware that a very inexpensive, dull, brownish zoisite can become a beautiful, expensive tanzanite after heat treatment.

TOPAZ - symbol of love and affection is the birthstone for November. It is one of nature's most wonderful and least-known families. The true topaz is rarely seen in jewellery stores. Unfortunately, most people know only the quartz (citrine) topaz, or glass. In the past almost any yellow stone was called topaz. True topaz is very beautiful and versatile. Topaz occurs not only in the transparent yellow, yellow brown, orangy brown, and pinky brown colours most popularly associated with it, but also in a very light to medium red (now found naturally in fair supply, although many are produced through heat treatment), very light to light blue (also often the result of treatment, although it does occur naturally on a fairly wide scale), very light green, light greenish yellow, violet, and colourless. Topaz is a hard, brilliant stone with a fine colour range, but it is much rarer and much more expensive than the stones commonly sold as topaz. There are many misleading names to suggest that a stone is topaz when it is not, for example, "Rio topaz," "Madeira topaz," "Spanish topaz," and "Palmeira topaz." They are types of citrine (quartz) and should be represented as such. Blue topaz has become very popular in recent years; most of it treated (there is no way yet to determine which have been treated and which are natural). It closely resembles the finest aquamarine (which is very expensive today) and offers a very attractive, and much more affordable alternative.

TOURMALINE - is a gem of modern times, but nonetheless has found its way to the list of birthstones, becoming an "alternate birthstone" for October. Perhaps this honor results from tourmaline's versatility and broad color range. Or perhaps to the fact that red-and-green tourmaline, in which the red and green occur side by side in the same stone, is reminiscent of the turning of October leaves. Whatever the case, tourmaline is one of the most versatile of the gem families. It is available in every color, in every tone, from deep to pastel and even with two or more colors appearing in the same stone, side by side. There are bicolored tourmalines (half red and the other half green, for example) and tricolored (one-third blue, one-third green, and one-third yet another color). The fascinating "watermelon" tourmaline looks just like the inside of a watermelon-red in the center surrounded by a green "rind." Tourmaline is a fairly hard,durable, brilliant, and very wearable stone with a wide choice of colours.

TSAVORITE- is a member of the garnet family and is often mistaken for other (usually more expensive) gems. It is one of the most beautiful, and all but a few would assume it was an emerald of the finest quality. In fact, it is "clearer," more brilliant, and more durable. There is also a rarer green garnet, called demantoid, which costs slightly more than tsavorite but which, although slightly softer, has more fire. These gems offer fine alternatives to the person desiring a lovely green gem who can't afford emerald. While still rare, expensive gems themselves, they are far less expensive than an emerald of comparable quality.

Return to previous page

Visit also the following pages in GEMMOLOGY WORLD: