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Each gem stone is unique and beautiful. They naturally occur within the environment and that they have to dug up to expose their magnificence and value. One of them is the Opal. This stone is an amorphous form of silica related to quartz, a mineraloid. It is deposited at a moderately low temperature and may be found in the crevices of almost any kind of rock. Opals are most generally found with limonite, sandstone, rhyolite, marl, and basalt. The Opal's internal structure causes it to diffract light. It may also come in various colors such as white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. It can even be clear. Stones with reds against black are the rarest of them to find; whereas, those with whites and greens are the most common. Furthermore, it can also be opaque or translucent. The veins of the Opal displaying the play of color are often quite thin; these also give emphasis on the remarkable methods of preparing the stone as a gem. Furthermore, when you test it with light, the thickness of the stone inhibits the visible light of diffracted wavelengths to pass through. Opals are also best known examples of optical band gap in a photonic crystal. In addition, you commonly see them as the most opaque gem stone with contrasting vein-like patterns when compared to the others. This beautiful stone has many varieties. The common Opal has subtypes namely the Milk Opal which has a milky, bluish to greenish quality; the Resin Opal which has a honey-yellow, resinous luster; the Wood Opal which is caused by the replacement of the organic material in wood; the Menilite which is brown or grey in color consistency; the Hyalite which is a colorless, crystal-clear variety and oftentimes known as the Muller's Glass; the Geyserite which is also siliceous sinter, is deposited around hot springs or geysers; and the Diatomite or Diatomaceous Earth which occurs as a result of the accumulation of diatom shells in the ground. Aside from the common Opal, there are also other known kinds such as the Fire Opals, Cantera Opal, Mexican Water Opal, Girasol Opal, Peruvian Opal, and the Pineapple Opal. Fire Opals are transparent to translucent stones with colors ranging from yellow, orange, orange-yellow, to red. They do not usually have any play of color, but the stones occasionally show bright green flashes. They are also known as Jelly Opals. The most famous source of this variety is the state of Querétaro in Mexico from which they are commonly called Mexican Fire Opals. On the other hand, the Cantera Opals are those that are hard enough to allow cutting and polishing. They are also found commonly in Mexico. The Mexican Water Opals are those that are colorless and exhibits either a bluish or golden internal sheen. Nevertheless, the Girasol Opal is a type of Halite Opal that exhibits a bluish glow or sheen that follows the light source around. This is not a play of color but rather an effect from a microscopic inclusion. Most commonly, this variety is sometimes mistaken for Opals that are transparent to translucent type of milky quartz from Madagascar which also shows asterism when cut properly. The Girasol Opal is also sometimes known as the Water Opal because it is found in Mexico as well. What is more, the Peruvian opal, otherwise known as the Blue Opal, is a semi-opaque to opaque blue-green stone found in Peru which is frequently cut to include the matrix in the more opaque stones. Aside from Peru, this variety can also be found in Oregon in the Owhyee region and in Nevada around the Virgin Valley. Lastly, the Pineapple Opal is the rarest among the varieties. It is only found in White Cliffs of New South Wales. This stone occurs as a result of deposition of various fossils and many of these fossilized forms contain the exceptional qualities of a noble Opal. It is also otherwise known as Pseudomorphs. When you look at it generally, it appears to be like a beautiful mural made out of stone because you can see the colors contrasting and gradually mixing in some areas. Its beauty is special and that makes it even more precious than it looks. Furthermore, because of its exquisiteness and splendor, it is commonly used in jewelry to grace a woman’s appearance. Click here for more information.
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