History & Introduction

The name Cat's eye comes from the feature displayed by this stone known as chatoyancy, which in French literally means “cat's eye”. In gemmological parlance, chatoyancy refers to an optical effect (a reflectance of sorts) that is seen in a few natural gemstones. After the chatoyant chrysoberyl is cut with a cabochon (domed surface), it shows a streak of light running in length from each of the end of the stones. These stones are termed as cymophane or cat's eye chrysoberyl.

It is available mainly in Sri Lanka (Ceylon) and Brazil, this gemstone shows chatoyancy in yellow, white, greyish- green, greenish-yellow. In fact you need to look out for cat's eye stones having a spot in the crystal, pale colour, cracks, stains or holes. With a cat's eye in hand, you can see a silver lining under direct sun or lamp light. The cat's eye effect is seen with a number of other gemstones like tanzanite, emerald, scapolite and aquamarine.

It is a believed that the wearer of cat's eye gemstone make the wearer wealthy and happiness in matters related to children too. This gemstone is considered to very quick acting gemstone, it is always advisable to use it after a trial. The users also need to be wary of dull stones that could signify bad health even spotted stones that shows enemy trouble. It is even said to improve the stamina, happiness and radiance. When evaluating the Opal Cat's Eye the important point to remember is the strength and sharpness of the eye. There is a fine line running through the eye of the stone, it is then distinct and easily recognized. Including to this, the body colour along with the quality of the play of colour is shown with the stone are also important factors that have an important effect on value, making pricing complex.

Among the finer gemstones, cat's eye tourmaline is tend to be available pink as green colour and in larger sizes also not uncommon. The popular is the tiger's eye available in gold-yellow and gold-brown, at first it is formed in to fibrous blue mineral known as crocidolite that is formed with iron and sodium. The crocidolite, then slowly is transformed into quartz while maintaining its fibrous formations.

Cat's Eye describes a gemstone polished into a cabochon that shows a narrow band of concentrated light going across the width of the stone. This effect is called chatoyancy, or cat's eye effect because of inclusions of fine, slim parallel mineral fibers in the gemstone reflecting light in a single band. Among the gemstones that show cat's eye, Chrysoberyl Cat's Eye is popular one. The intensity of Cat's Eye varies from strong to weak. The clarity as well as the intensity of the cat's eye band will play an important role in the value of a Cat's Eye gemstone. The effect of bright and straight light is maximum desired, and when strong and perfect it will be highly treasured. In some forms of Chrysoberyl, the cat's eye effect is weak that look like a billowy, floating light reflection as opposed to a bright with a concentrated band of light. Such Chrysoberyl is termed with Cymophane, and cymophane effect is termed as the effect.

Availability - Cat's Eye sources are in Brazil, India, China, and Zimbabwe.

Usages - Cat's Eye is polished into cabochons, and is used most often in rings and pendants.

Buying Guide

Colour - In case of the softer gemstones, the cat's eye effect is frequently available in the gemstone apatite, in golden colour somewhat reminiscent of chrysoberyl. The other colours available are colourless, green, pink, blue, yellow and violet. The effect of cat's eye is seen in a number of other varieties of gems, however very rarely. They are emerald, iolite (also known as cordierite), tanzanite, aquamarine, andalusite and scapolite. These items are considered to be real collectors if you can find them.

Cut and Lustre - Opal Cat's Eyes are most commonly and almost exclusively cut into cabochons. The reason is due to the tall, round cut is needed to maximize the striking Cat's Eye effect most brilliantly.

Chrysoberyl cat's eye belongs to the same family as the rare alexandrite. Since chrysoberyl is a very hard stone this makes it suitable for all kinds of jewellery. Opal Cat's Eyes are sometimes impregnated with colourless plastic in order to improve and enhance durability.

Among the gemstones showing the special optical phenomena, in part because the effect is available in various kinds of gem varieties. Chatoyancy is the technical term for the cat's eye effect, comes from the French word denoting eye of the cat ("oeil de chat").

The effect of the stone resembles like the slit eye of a cat. The effect is caused because of the reflection of light with parallel fibres, needles or even channels in the gemstone. Commonly, the gemstone requires to be cut en cabochon with the base in parallel with the fibres to show this effect. When the gem is rotated, the cat's eye appears to glide over the surface.

Treatment - Chrysoberyl Cat's Eye is not treated or improved.

Gemmological - Chrysoberyl Cat's Eye is not treated or improved.

Gemmological Characteristics:

Orthorhombic

Chemical Formula	SiO2n.H2O
Color	Blue, Brown, Red, Purple, Green, Yellow, Orange, Pink, Grey, Multi-coloured
Hardness	8.5
Crystal System	8.5
Crystal System Refractive Index
Refractive Index SG	From 3.5 to 3.8
Transparency	Translucent
Double Refraction	.009
Lustre	Vitreous
Cleavage	1,1 ; 3,2
Mineral Class	Chrysoberyl

Classification:

• Cat’s eye apatite
• Cat’s eye aquamarine
• Cat’s eye moonstone
• Cat’s eye tourmaline
• Cat’s eye chrysoberyl
• Cat’s eye emerald