There are three forms of the chrysoberyl family: alexandrite, chrysoberyl and cat's-eye.

Chrysoberyl is a transparent, very brilliant stone that rates 8.5 on the Moh scale. It is found in green shades, ranging from clear, pure green to yellowish greens. It is usually moderately priced, despite its enormous popularity, and makes for an excellent purchase if you find a good quality grade stone. There is a variety of chrysoberyl that displays the cat's-eye effect, and theses are prized stones within the category. It should be priced at about $50-$300 per carat for anything smaller than 5 carats and about $150-$800 for anything larger than that.

Cat's-eye is often a confusing name for many people, as there are many gem-types (for example: quartz, tourmaline and beryl) that display the cat's-eye effect , but they are not real cat's-eye gems. The unmodified term refers specifically to the chrysoberyl cat's-eye , and any other gem called so merely indicates the similar effect it displays and should be referred to by their mineral name, as well as the affect they display, such as “cat's-eye quartz” and so forth. The major sources for this gem are Brazil and Sri Lanka , though they are sometimes found in Russia , Madagascar , Tanzania , Burma and Zimbabwe .

Cat's-eye is a lovely, durable gem rated 8.5 on the Moh scale. It is either golden yellow with a coffee brown slit through its mid-line or yellowish green with a dark green slit. The golden-brown variety is the most expensive, with fine quality gems displaying the eye effect clearly costing several thousands of dollars per carat weight. Slightly less expensive are the green-yellow variety, though as always, quality and size determine final value. The smaller, fuzzier gems can cost as little as $70-$100 per carat weight and are very popular around the world. Good grade gems can cost about $800-$6000 for anything smaller than 3 carats. For 4 or 5 carat cat's-eye the prices go up to $1500-$7000 per carat weight, depending on the exact grading.This gems appearance is remarkable not only because of the eye-effect, which is a result of fiber-like inclusions, but its also known for its velvet-seeming texture, that is a chrysoberyl feature. Cat's-eye is so soft looking its almost illusionary, displaying deep, silky lines of light reflections in its center and white glowing lines that make it seem as if the gem is lit from the inside out.

The general misconception is that cat's-eye and tiger's-eye are of the same type and variety. This is not so- cutting techniques and clever mounting may blur this distinction, making a tiger-eye seem darker than it actually is. Tiger's-eye is the far more common quartz variety and has weaker color and thus costs less per carat weight. Cat's-eye is deeper and more brilliant by far. You can distinguish between the two by viewing the stone unmounted and by a single, strong light. Holding it between your fingers, you will see that a fine-grade cat's-eye has its strip splitting it directly in the middle of the stone and the color is truly murky with internal stripping. If the line is not in the middle, this reduces value per carat weight. Remember that there are a lot of imitations in the market, and very often quartz cat's-eye is presented as the real thing. Verify the authenticity of the stone, or if you cannot- have the store write the stones mineral composition on the receipt so that you may return it if it turns out to be a fake.