Question:
What is opal? How’s that? What are the characteristics?

Answer:
opal
opal (Cat’s eye), the “cat’s-eyes”, “cat eye”, “cat fine.” Cat’s Eye Stone is also called the Oriental cat’s eye, is rare and precious jewelry in the species. As shown by opal light phenomena and the cat’s eyes, as bright and flexible to change with the strength of light, hence the name. This optical effect, known as “cat’s eye effect.”

gem with a lot of cat’s eye effect. Gem scholars to have a chrysoberyl cat’s eye effect known as Cat’s Eye, the general said, referring to the Cat’s Eye Chrysoberyl cat’s eye gem, while the other has a cat’s eye effect of the gems, to be in the “cat’s eye” before the word with precious stones names, such as aquamarine cat’s eye, tourmaline cat’s eye and so on.

Cat’s Eye in the mineralogy is chrysoberyl (Chrysoberyl) in one of case of spinel-group minerals. Chrysoberyl is a beryllium-containing aluminum oxide, the chemical formula BeAl2O4. Is orthorhombic. Crystal form Changchengnongxing short cylindrical or plate-like. Cat’s Eye Stone has a variety of colors, such as honey yellow, brown yellow, wine yellow, brown, yellow, and green, cinnamon, gray green and so on, of which the most valuable honey yellow. Transparent to translucent. The glass to the oil sheen. Refractive index 1.746-1.755, double-refractive index of 0.008-0.010. 2 color obviously, dispersion 0.015, non-homogeneous body. Hardness of 8.5, density 3.71-3.75 g / cubic centimeter. Conchoidal fracture.

cat’s eye cat’s eye gem stone and other similar man-made cat’s eye the difference. Nature can produce cat’s eye effect gems are tourmaline, beryl, apatite, quartz, kyanite, etc., but not as good as gold precious green cat’s eye. Tourmaline Cat’s Eye: hardness smaller, in order to 7-7.5, density 3.06 grams / cubic centimeter, refractive index 1.624-1.644. Quartz Cat’s Eye: Hardness is low, 6.5 or so, low density, 2.78 g / cc, refractive index is small, 1.44. Synthetic Cat’s Eye: From a result of artificial opal glass fiber, there is brown yellow, blue and red. But the man-made opal also occur in the arc of the top 2-3 band of bright, natural opal appears only a bright band. Observed with a magnifying glass can be seen artificial opal have hexagonal honeycomb structure, hardness is low, 5 or so, low density, 2.46 g / cc, refractive index 1.44. Cat’s Eye Stone

evaluation and purchase. Cat’s Eye Stone’s assessment is from the color, eye liner position, gem shape, weight and other factors to consider. High-quality cat’s eye gems, cat’s eye line is to be thin and narrow, clear boundaries; Zhang closed eyes, a flexible, significantly living light; cat’s eye color in sharp contrast with the background; and cat’s eye line is to be located in the central arc. When you purchase your cat’s eye according to identifying characteristics of the cat’s eye stone and other precious stones, synthetic cat’s eye to distinguish, buy genuine opal.

in Southeast Asia, cat’s eye stone is often seen as a symbol of good luck, people believe that it will protect the owner and healthy life, freedom from poverty. Cat’s Eye is often known as the “noble gem.” It changed its precious stones with high-grade stones are one of the world’s top five. British gem collector with a well-known treasure Hope Cat’s Eye stone, this stone was carved the shape of a symbol of the altar, on top of a torch, the whole gem spherical, diameter of about 1-1.5 inches. Cat’s Eye Stone mainly produced in the gas into the hydrothermal deposits and pegmatites in Dyke. The world’s most famous opal origin southwest of Sri Lanka特拉纳布拉and Al Gore and other places, Brazil and Russia and other countries are also found in cat’s eye stone, but very rare.