What is the cat's eye effect?
Cat's eye effect is an optical effect mainly caused by the refraction and reflection of light by a group of dense, parallel-oriented inclusions or structures in a curved gem. When illuminated by parallel rays, the surface of the gem will show a bright band of light, and this band will move with the stone or light. If the gemstone is placed under two light sources, the eyeliner of the gemstone will appear open and closed, and the flexible and bright cat's eye is very similar, therefore, people call this phenomenon of gemstones "cat's eye effect".
A gem with a cat's eye effect
In natural gemstones, many gemstones can produce cat's eye effect after special cutting and grinding due to their inherent nature, but not all gemstones with cat's eye effect can be called "cat's eye". Only chrysolite with cat's eye effect is entitled to be directly called "cat's eye" or "cat's eye". Other gems with cat's eye effect usually add the name of the gem before "cat's eye", such as quartz cat's eye, silylene cat's eye, tourmaline cat's eye, emerald cat's eye, etc.
Chrysoberyl cat's eye
Chrysoberyl cat's eye is often called the "noble gem". It is considered a symbol of good luck and is believed to protect its owner from a long and healthy life and from poverty.
Chrysoberyl cat's eye can show a variety of colors, such as honey yellow, yellow green, brown green, yellow brown, brown and so on. Under a concentrated light source, half of the gemstone shows its body color to the light, and the other half appears milky white. Its gloss is glass to grease gloss, transparent to translucent.
The evaluation of chrysolite cat's eye is based on factors such as color, light, weight and perfection. High-quality chrysolite cat eye, eyeliner should be thin and narrow, clear boundaries; The eyes should be open and closed flexibly, showing a living light; The cat's eye color should be in sharp contrast with the background; And the cat's eye line should be located in the center of the arc.
Cat's eye is often produced in Sri Lanka's placer mines and is also found in countries such as Brazil and Russia, but it is very rare.
Quartz cat's eye
Quartz cat's eye is quartz with cat's eye effect. Quartz containing a large number of needle-like inclusions or fine tubes, when ground into a curved stone, will have a cat's eye effect. The light band of the quartz cat's eye is usually not as neat and clear as the light band of the chrysoberine cat's eye, so it is usually processed as a ring, beads, and large grain sizes can be used for carving crafts.
Quartz cat eyes are rich in color, from white to grayish brown, yellow-green, black or light to dark olive are available, the common color is gray, which has a narrow cat eye line, tan background color for the finished product. The refractive index and density of quartz cat eyes are much lower than that of chrysoberyl cat eyes, so the eyeliner on the body surface looks less bright and weighs less. Its main production areas are India, Sri Lanka, the United States, Mexico, Australia and so on.
Silylene cat eyes
Sillimanite is mainly used in the manufacture of high-aluminum refractory materials and acid-resistant materials, beautiful color can be used as gem raw materials, single crystal can be ground into faceted gems, the domestic market sillimanite cat's eye is not rare.
Sillimanite cat's eye is very common in cats, and basic gemstone grade sillimanite has cat's eye effect. The inclusion of rutile, spinel and biotite can be seen in sillimanite under microscope. These fibrous inclusions are arranged in parallel, creating a cat's eye effect. Sillimanite cat eyes are usually grayish green, brown, gray, etc., translucent to opaque, rarely transparent. Fibrous structures or fibrous inclusions can be seen when enlarged, and the eyeliner is diffused and inflexible. The polarizer can present four bright and four dark or a collection of polarized light. Sillimanite cat's eye has low refractive index and relative density. It is mainly produced in India and Sri Lanka.
Tourmaline cat eye
The English name Tourmaline is derived from the ancient Sinhalese word "Turmali", which means "mixed gem". Tourmaline is beautiful in color, rich in color, hard in texture, and is loved by the world.
Cat's eye is a kind of tourmaline. When tourmaline contains a large number of parallel fibrous and tubular inclusions, which are ground into curved stones, cat's eye effect can be displayed. Common tourmaline cat eyes are green, a few are blue, red and so on. Tourmaline cat eye production is relatively small, the collection value is also higher. Brazil is famous for producing tourmaline cat's eyes.
Emerald cat eyes
Emerald is an important and precious variety of beryl, known by the world as "the king of green gems", which guarantees success and love.
The number of emerald cat eyes on the market is very small, can be described as rare rare, the price of better quality emerald cat eyes is often much higher than the price of the same quality emerald. Emerald cat's eyes are found in Colombia, Brazil and Zambia.
Post time: May-30-2024