Cat's Eye Tips

There are many gemstones with a cat-eye effect. The gemologists call the gold-green sapphire with the cat-eye effect cat's eye, and the cat's-eye refers to the gold-green cat's-eye gems. Other gems with the cat-eye effect must be preceded by the word “cat's eye.” Names such as aquamarine cat's eye, tourmaline cat's eye, etc.

Strictly speaking, the "cat's eye" is not the name of a gem but an optical phenomenon present on certain gemstones. When a semi-spherical gemstone is illuminated with bright light, a narrow and bright reflection appears on the surface, called "cat's eye flash" or "cat's eye light," and is named according to what the gemstone is. If the gemstone is quartz, it is called. "Quartz cat's eye", if it is gold emerald, it is called "gold green cat's eye". There may be many types of gemstones that may have flashes of cat's eyes. According to statistics, there may be as many as 30 species. In addition to the quartz cat's eyes and gold green cat's eyes that are more common on the market, there are "pseudo-pseudo-eye" and "aquamarine cat's eye". Because the gold green cat's eye is the most famous and precious, it is also commonly referred to as "cat's eye". Other cats' eyes are not so called.

Cat's eye is a kind of Chrysoberyl in mineralogy and belongs to the mineral group of the gold green gems. Gold emerald is a lanthanum-containing aluminum oxide with the chemical formula BeAl2O4. Orthorhombic system. The crystal form often has a short column or plate shape. Cat's Eye has a variety of colors, such as honey yellow, brown yellow, burgundy, brownish yellow, yellowish green, yellowish brown, grayish green, etc., among which honey is the most valuable. Transparent to translucent. Glass to grease sheen. The refractive index is 1.746-1.755 and the birefringence is 0.008-0.010. Dichroism is apparent, dispersion is 0.015, anisotropic. Hardness 8.5, density 3.71-3.75 g/cc. Conchoidal fracture.

The difference between the yellow cat's eye ball and other similar gem cat's eyes and artificial cat's eyes. The gemstones that can produce the cat's eye effect in nature are tourmaline, beryl, apatite, quartz, kyanite, etc., but they are not as precious as gold green cat's eyes. Tourmaline Cat's Eye: Hardness, 7-7.5, density 3.06 g/cm3, refractive index 1.624-1.644. Quartz cat's eye: The hardness is low, about 6.5, the density is small, it is 2.78 g/cm3, the refractive index is small, it is 1.44. Artificial cat's eye: Cat's eye caused by artificial glass fiber, with brown yellow, blue and red. However, the artificial cat's eye shows 2-3 bright bands at the top of the arc, and only one bright band appears in the natural opal. Observation with a magnifying glass revealed that the artificial cat's eye had a hexagonal honeycomb structure with a low hardness of about 5, a low density of 2.46 g/cm 3 , and a refractive index of 1.44.