Gemstone :
Opal Cat's Eye

Birthstone Month :
Opal is the gemstone associated with the month of October.

Zodiac :
Opal is associated with the zodiac signs of Libra and Scorpio.

Chemical Symbol :
SiO2n.H2O

Chemical Make-up :
Opal is a Hydrated Silicon Dioxide that lacks a distinct crystalline structure. Opal contains between 2 and 21 percent water within its mineral structure

History & Lore :
Opal is derived from the Latin word 'Upala' and the Greek word 'opallios', both meaning “precious stone”. The name Cat's eye is derived from the phenomena displayed by this stone known as chatoyancy, which in French literally means “cat's eye”.

The Roman scholar and famous author Pliny once described Opal as a gemstone that combines the best possible characteristics of the most beautiful of gemstones: the fine sparkles of Almandine, the shining purple of Amethyst, the golden yellow of Topaz, and the deep blue of Sapphire, “so that all all colors shine and sparkle together in a beautiful combination.”

In Greek mythology, Opal was believed to be formed from the joyous tears wept by Zeus after he defeated the Titans. It was also believed by the Greeks that the owner of Opal would obtain the power of giving foresight and the light of prophecy.

In ancient Arabic times it was believed that opals fell from the heavens in lightning, the flashes giving the stone its fire and flare.

It is said that Opal was part of Cleopatra's famous jewelry collection, and that she used the stone to attract the attention of Mark Anthony.

Opal is said to be a symbol of faithfulness and is believed to assist the wearer with finding true love. Opal is also believed to cure depressions and bring confidence to the wearer. Opal helps to open unused parts of the mind in order to increase creativity and mental capacities.

Availability :
Opals were relatively rare until the mid 19th century, when there was a rich discovery in Australia that has supplied enough Opal to meet market demand ever since.

Sources :
Australia is the World's most important source of Fine Opals, and is estimated to account for almost 95% of all mined Opals. There are also known Opal deposits in Brazil, the Czech Republic, England, Honduras, Mexico, South Africa, and the United States.

Evaluation :
Opal is rated at 5.5 to 6.5 on Moh's Scale of Hardness and is a relatively soft and fragile gemstone. The physical structure of Opal is unique. Tiny spheres of silicon dioxide form a pyramid shaped grid interspersed with water. Tiny natural faults in this grid cause the characteristic "play of color". The effect is similar to the rainbow colors displayed on a soap bubble, only much more dramatic. Opals vary widely in body color, with white the most common. Black is considered the most valuable color as it enhances and accentuates Opal's unique play of color. Fire Opal (yellow, orange or red), is often faceted and can sometimes resemble Ruby. Green and Blue Opals are very rare and per Carat prices reflect this.

Opal Cat's Eyes display an amazing phenomena known as chatoyancy, also known in the gem trade as “the cat's eye effect”. The reason for this fascinating phenomenon is very fine inclusions within the stone. When a light source is directed on these inclusions it creates a bright strip that appears, running perpendicular to the inclusions. This strip will then glide across the surface of the stone when turned over.

The most important factor to consider when evaluating Opal Cat's Eye is the strength and sharpness of the eye. The eye of the stone must have a fine line running through it that is distinct and easily recognized. In addition to this, the body color and the quality of the play of color exhibited by the stone are also important factors that have a significant effect on value, making pricing quite complex.

Common Cuts :
Opal Cat's Eyes are most commonly and almost exclusively cut into cabochons. This is because a tall, round cut is required to maximize the striking Cat's Eye effect most brilliantly.

Routine Enhancements :
Opal Cat's Eyes are sometimes impregnated with colorless plastic in order to improve and enhance durability.

Care & Cleaning :
Opals are relatively soft gemstones and should be worn with special care because they are prone to scratching and chipping. Always avoid sudden temperature changes with Opals as this can can cause the stone to crack or craze. Because Opals are composed of a small percentage of water, always be careful not to allow them to freeze or dry out. It is recommended that you have Opals cleaned by a professional jeweler. If home cleaning is undertaken it should be done using room temperature water and a mild detergent. A soft brush or cloth can be used safely. Always store your opal jewelry in a fabric-lined box alone, or away from other harder jewelry items in order to avoid damage.