Tuesday

All About Gemstones

Gemstones in their many shades of color have fascinated mankind for thousands of years. The ancients attributed magical, mystical powers to each stone, and believed that many of them could cure specific ailments. Even today, we revere colored stones as beautiful, unique, and as a means of personal expression and individuality for their wearers.

Amethyst: The Color for Kings

Amethyst has long been a favorite gem of kings and queens for its royal purple hues. The gem, the most precious member of the quartz family, exhibits color ranging from pale lilac to deep purple. Amethysts are featured in the British Crown Jewels and were worn by Catherine the Great as well as Egyptian royalty.

Through the ages, various special properties have also been prescribed to amethyst. The Greeks and Romans considered it a strong antidote against drunkenness and drank wine from goblets carved out of the gem. Leonardo Da Vinci wrote that amethyst could dissipate evil thoughts and quicken the intelligence. The stone also is supposed to bring peace of mind to the wearer and prevent fatal poisoning.

In some legends, the stone also represents piety, celibacy and dignity. In Tibet, for instance, amethyst is considered sacred to Buddha and rosaries are often made from it. In the Middle Ages, the gem was an important ornamentation for the Catholic Church and other religions. In fact, it was considered the stone of bishops, and they still often wear amethyst rings.

The birthstone for February, amethyst is an extremely popular gem for jewelry because of its regal color, variety of sizes and shapes, affordability and wide range of hues. It also is the recommended gem for couples celebrating their sixth wedding anniversary.

The stone is mined in Brazil, Uruguay, Bolivia and Argentina, as well as in Zambia, Namibia and other African nations. Very dark amethyst in small sizes also is mined in Australia. But the ideal for fine quality amethyst was set by a Siberian variety, often called Russian or Uralian amethyst, which is now considered a defunct source.

Generally, South American amethyst tends to come in larger sizes than African amethyst. But the African variety has a reputation for having deeper color intensity and is therefore considered more valuable. The African version also is harder to come by than amethyst mined from South America. Most of today's amethyst comes out of Brazil.

The finest and most valuable amethysts are very clear, with very deep color (and they sometimes exhibit reddish or rose overtones). Some stones are so oversaturated with color they have areas that are blacked out, which can negatively impact their value.

Amethyst is available in a wide range of calibrated sizes and shapes, including many fancy cuts. Large fine stones are sold in free sizes but generally the stone is cut in standardized dimensions. Paler shades, sometimes called "Rose of France", were common in Victorian jewelry. Banding - darker and lighter zones of color - is also a common occurrence. Occasionally, amethyst is even found combined with its sister quartz citrine into a single stone called ametrine.

The most common enhancements to amethyst are heat and irradiation. The stone, which ranks a 7 on the Mohs hardness scale, is considered durable enough for everyday wear. However, care should be taken not to expose the gem to excessive amounts of bright sunlight, as this can cause its color to fade.

Aquamarine: Gem of the Sea

Aquamarine derives it name from the Latin term for seawater - and one look at this elegant gem's blue hues easily explains why.

According to legend, aquamarine was the treasure of mermaids and had the power to keep sailors safe at sea. It was also thought to possess a number of other mystical properties, including the ability to help couples smooth out their differences; protect against the wiles of the devil; cure headaches, insomnia and other ailments; quicken the intellect; and attract new friends. It is the symbol for youth, hope, health and fidelity.

It is also the birthstone for March and the recommended gem for couples celebrating their 19th wedding anniversary.

A variety of the mineral beryl, like the emerald, aquamarine is found in many exotic places around the world, including Afghanistan, Angola, Kenya, Madagascar, Mozambique, Nigeria, Pakistan, Sri Lanka, Russia, Zambia and Zimbabwe. But most of the gemstones available in the market today come from Brazil.

Aquamarine is found in a range of blue shades, from pale pastel to greenish-blue to deep blue. Deeper colors are unusual in smaller sizes; generally, it takes a larger stone to hold a darker shade. The most prized aquamarines are those displaying a deeper, pure blue, with no green tints. These are rarer and therefore more valuable. But if you prefer those with a greenish hue, you should be able to get them for a bargain price.

Like with any gem that is pale, aquamarines should be "eye clean" (no inclusions visible to the naked eye), since internal flaws are more noticeable in a pastel stone. This shouldn't be much of a problem - unlike its emerald sister, aquamarine is known for being relatively free of inclusions. This is why aquamarines are frequently cut with large step facets to show off their flawless surfaces. The most popular cuts for aquamarine are oval and emerald.

Settings for aquamarine can also safely expose more of the gemstone than is possible with emerald. Aquamarine's tendency toward having few inclusions makes it less susceptible to nicks or cracks than many other gems. With an "8" ranking on the Mohs hardness scale, the stone is very durable and can stand up to everyday wear. Its clear, pale brilliance makes it an appropriate stone for all types of jewelry - and it combines well with all jewelry metals and is flattering to most skin tones.

Aquamarine is commonly heat-treated to permanently remove green overtones. Unlike its sister stone the emerald, aquamarine generally isn't plagued by surface fractures - which means the stone isn't usually treated with fillers, resins or oils. Even so, avoid mechanical cleaners. To clean aquamarine, use warm soapy water.

The largest known aquamarine is a 243-pound stone found in Brazil in 1920. It was cut into many smaller stones and a 13-pound uncut piece resides in the American Museum of Natural History. Another noted aquamarine is an 879.5-carat flawless, step-cut, sea green stone on display in the British Museum of Natural History.

Blue Topaz: Birthday Blue

Blue topaz has become one of the most popular gemstones on the market today, due to its clarity, durability, availability and affordable cost. Yet it is a shade of topaz rarely found in nature. The stone's watery blue color is most often created through a combination of heat treatment and irradiation.

Topaz is one of the well-known pegmatite minerals that also includes beryl and tourmaline. Blue topaz is the birthstone for December - and is also the recommended gemstone for couples celebrating their fourth wedding anniversary.

Blue topaz has a definite, uniform color ranging from sky blue to Swiss blue. It is sometimes confused with the more costly aquamarine - yet whereas aquamarine sometimes has a greenish-blue or bluish-green tint, blue topaz will always look blue or bluish gray. The one exception is for surface-enhanced topaz, a process introduced in 1998 that enhances the stone's appearance and brings out colors such as blue to greenish-blue to emerald green.

Most blue topaz starts life as a colorless or slightly tinted topaz from places like Brazil, Mexico, Nigeria, Sri Lanka and China. It is then irradiated (to incite the color change) and heated (to stabilize the change). The result is a permanent aqua shade. To get deep blue color out of topaz, treaters use neutron bombardment in a nuclear reactor and market the final product under the name "London blue." In fact, neutron bombardment is the only means by which to produce smaller calibrated stones with deep color.

Despite the stone's exposure to irradiation, experts say it poses no health hazard whatsoever to the wearer.

In addition to blue, the stone comes in a variety of colors, including golden yellow, orange-yellow, reddish-orange, sherry red, deep pink, honey brown, light green, and many shades in between.

Topaz holds the distinction of being the gemstone thought to have the widest rage of curative powers. According to legend, the stone can dispel enchantment and improve the eyesight. The ancient Greeks believed that it had the power to increase strength and make its wearer invisible in times of emergency. Topaz is also said to change color in the presence of poisoned food or drink. Throughout history, different cultures have believed that the stone could cure insomnia, asthma and hemorrhages; bring friendship; promote patience and a pleasant disposition, and ensure fidelity. To the ancients, it was also a symbol of love and affection and was even thought to ward off sudden death.

With a ranking of "8" on the Mohs scale of hardness, blue topaz is exceptionally strong and durable and well-suited to everyday wear. However, it should be protected against hard blows that can split, crack or chip it.

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