Semi-Precious Stones Colorado

When thinking of the most valuable gemstones on earth, Alexandrite would probably not jump to mind. But these amazing color change stones are so rare and beautiful that they can easily command $20,000 per carat for large top quality specimens. Fine large examples of this gem are so prized that even a one carat stone can sell for $10,000 per carat. How many gems share that lofty distinction?

A relative newcomer to the gem world, discovered in Russia in 1830 on the twelfth birthday of Czar Alexander II (hence the name) these stones exhibit a lush-grassy green in daylight and brilliant raspberry red under incandescent lighting. Red and green also happened to be the colors of the Russian Imperial Guard. Alexandrite was instantly believed to bear good omens.

The Russian source has long been depleted, and today's Alexandrite is predominantly produced in Sri Lanka. The quantity and size of alexandrite rough from Sri Lanka has been phenomenal, but the quality and brilliance of color change (Sri Lankan stones are more yellowish-green outdoors, and the red tends toward brown under artificial light) rarely measures up to the vivid hues found in Russia.

Unlike garnet and other stones with a color change variety, alexandrite will always exhibit a distinct change of color. Therefore, the more vivid each color and the more distinct the change, the more valuable the stone.

The true test of color change must be performed in a dark room with a single light source (preferably candlelight to bring out the red.)

Clarity also plays an important role in valuing alexandrite. Any flaws that block even color distribution will dramatically reduce the price.

On the other hand, inclusions are precisely what give cat's eye chrysoberyl its special effect. Although completely different in appearance, both cat's eye and alexandrite are from the mineral chrysoberyl. Tourmaline and other stones have a cat's eye variety, but the term when used alone always refers to chrysoberyl. Ranging from misty yellow to brownish-yellow, the most valuable hue is a rich-deep honey-yellow, and top quality specimens can fetch an impressive $5,000 per carat. Without the sharp eyes, though, the price can drop drastically to under $100 per carat.

As a member of the quartz family, amethyst is one of the most common, hence under-appreciated, gemstones on the market. Yet, its affordable beauty due to abundant availability also make amethyst extremely popular. A transparent rich lavender with flashes of red and pink at its finest, this birthstone for the month of February, and 6th wedding anniversary stone, will normally cost less than $100 per carat. Top quality specimens are found in Brazil and Zambia and will display an intense, deep-purple that is uniform throughout the stone. Color zoning and flaws that render a stone less than "eye-clean," greatly reduce value. It is estimated that over half of all amethyst on today's market is man-made, or a natural/man-made blend called "salted" amethyst. Amethyst can lose its color if heat treated, and care should be taken not to expose it to sudden temperature changes or overexposure to sunlight.

There are actually a number of gem quality quartz varieties available, of which amethyst is the crowned prince. Citrine, a yellow or orange quartz, is also quite popular. Partly because it is often sold as topaz, but also due to its marketability as the 13th wedding anniversary stone as well as being November's alternate birthstone. Almost all citrine is actually amethyst or smoky quartz (a brown or black variety) that has been heat-treated to produce its unique citrus glow.

Ametrine, the baby of the quartz gem family, appeared on the market just over a decade ago. Instantly a favorite, this purple and yellow zoned stone blends its colors in exotic patterns of breathtaking beauty.

Other varieties include the famous Rose quartz (pink) rock crystal (the colorless type that is seen everywhere) prasiolite (amethyst heated to yellowish green) drusy (small, shiny layers of crystals found in rock cavities) as well as opaque, satiny cat's and tiger's eye varieties, to name a few.

The name "quartz" comes from the Slavic "kwardy" for hard and has been used by humans since prehistoric times (evidenced by archeological finds of quartz tools and jewelry dating to 20,000 B.C.) Quartz has been revered for its magical powers for thousands of years, probably due to its electroconductitivy (squeeze one and it becomes charged, run a current through it and it vibrates with a frequency so stable, its synthesis is used to keep time in quartz watches.)

Amethyst and other quartz gemstones deserve a second look. At their finest, they can offer years of enjoyment, pleasure and compliments at very affordable prices.

For many years Iolite was predominantly employed as a cheap substitute for blue sapphire and tanzanite. Commonly referred to as water or lynx sapphire, these brilliant blue gemstones are one of the best buys on the market today. But don't procrastinate too long, for iolite is quickly gaining in popularity in its own right. Right now, you can still get high quality iolite for under $200 per carat. This is a bargain considering its naturally deep blue face-up appearance. This 21st wedding anniversary stone also claims a unique property that sapphire and tanzanite cannot claim: aside from facing-up sapphire blue, it will appear gray to yellowish or colorless from another direction and light blue or violet from yet another (an effect called trichroism.)

Iolite gets its name from the Greek, "ios" for violet, and ranges in color from deep blue to light blue, gray and yellowish blue-gray. The world's main resources for iolite are Sri Lanka, Brazil, Myanmar (Burma) Madagascar, Canada, India, Tanzania and Namibia. Some of the Sri Lankan iolite is called "bloodshot iolite" when a peculiar inclusion is present that causes a stone to appear red if viewed from certain angles. Iolite is generally "eye-clean" and is fairly hard (7 to 7.5 on the Mohs scale.)

Iolite has been found in ancient Columbian remains, and the Vikings used to use the stone as a compass on cloudy days as its trichroic qualities allowed them to find the sun through the fog.

So, if it's blue you want, check out this baby blue before it gets too popular. You just may find yourself way ahead of the pack.