Gem Library

BUYER’S OVERVIEW:
Tiger’s Eye is considered to be a semi-precious gemstone. Abundant in nature, large, clean natural stones are available. Named for its glowing resemblance to a Tiger’s Eye, this gem has been used in jewelry and carvings for centuries. With exotic names like Tiger’s eye, Hawk’s eye, and Tiger Iron, it comes in a range of colors from brownish yellow to a grayish blue and is the best known example of the phenomena of Chatoyancy (a striking, play of light and movement over the surface of the stone). Chatoyancy can be described as a three dimensional glow of color that appears to float over the base color (usually brown) of the stone. In the case of Tiger’s Eye, you see a golden yellow shimmer over the brown base of the stone.

Marra Mamba, a form Tiger’s Eye found in the Hamersley Ranges of the Pilbara region, often exceeds Pietersite in terms of value and desirability. Now very rare it contains shades of red, green, yellow and blue.

COLOR:
Tiger’s Eye comes in a range of colors, from a brownish yellow, through brown, reddish brown and grayish blue.

APPEARANCE:
Semi-transparent to opaque.

Phenomena: Tiger’s Eye exhibits Chatoyancy, a wavy three-dimensional color effect.

SIZE RANGE:
1 – 20 carats, cabochons over 1000 carats are known.

TYPICAL CUTTING STYLES:
Semi-transparent to opaque: beads, cabochons, intaglios and carvings.

POSSIBLE ENHANCEMENTS & TREATMENTS:
Tiger’s Eye is sometimes heated or bleached, both treatments are stable and undetectable.

HARDNESS:
7 on the Mohs scale.

BEST USE OF THE GEMSTONE:
Tiger’s-eye can be used in all types of jewelry.

CARE & CLEANING:
It is best to never expose colored gemstones to cleaning solvents or chemicals of any kind.
Common cleaning methods include:
Ultrasonic: usually safe
Steamer: risky
Warm soapy water: safe
Reaction to Chemicals: can be damaged by acids.
Reaction to Heat: heat may alter the stone’s color, fast temperature changes may fracture it.
Stability to Light: stable.

INTERESTING FACTS ABOUT THIS GEMSTONE:
Tiger’s Eye is a Pseudomorph, from the Greek for “false form”. Pseudomorphs form when one mineral replaces another, similar to what happens when quartz replaces wood to produce petrified wood. Tiger’s Eye formation begins when quartz becomes imbedded between the fibers of a blue mineral called crocidolite (which we know as asbestos). This process results in one of two gemstones; a blue stone called Hawk’s Eye or golden brown Tiger’s Eye. During the process, the asbestos is completely dissolved and the quartz takes on the fibrous formations and the blue color of crocidolite. This is what creates the shifting play of light and movement (Chatoyancy) that the stone is known for. The gemstones color is caused by the hydrated oxide of iron and varying amounts of this will cause several colors, a golden yellow reflection on a brown stone, is called Tiger’s Eye and a blue gray or bluish stone is known as Hawk’s Eye. Reddish brown, or mahogany colored stones are known as bull’s-eye or ox-eye.

Soon after its discovery in the late 19^th century, lapidaries found they could bleach Tiger’s Eye to an evenly colored light yellow. When properly oriented and cut the stone could yield a sharp cat’s-eye, reminiscent of “real” cat’s-eye, an expensive variety of chrysoberyl. The most important deposits of Tiger’s eye are in South Africa and Western Australia. Marra Mamba, a form Tiger’s Eye found in the Hamersley Ranges of the Pilbara region, often exceeds Pietersite in terms of value and desirability. Now very rare it contains shades of red, green, yellow and blue.

DESIGNATION:
Tiger’s Eye is the gemstone selected to honor the 9^th anniversary.

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