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Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al 2 Si O 4 (F, OH) 2.It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden brown to yellow-orange. [7]
2nd row: rare purple topaz, champagne coloured topaz on albite, rare topaz and green hydroxylherderite matrix. 3rd row: naturally cut topaz, irradiated blue topaz, white topaz on matrix Rare purple-lavender hued topaz on a matrix from Katlang in Mardan District, Khyber Pakhtunkhwa [1] [2] There are many types of gemstones of Pakistan.
^ Colorado is the only state whose geological symbols reflect the national flag's colors: red (rhodochrosite), white (yule marble), and blue (aquamarine). ^ Florida's state gem, moonstone, was adopted to highlight Florida's role in the United States' Lunar program, which landed the first astronauts on the Moon. [81]
Both diamonds and white topaz may phosphoresce if heated below red heat. The phosphorescent quality of diamonds when heated by sunlight is usually believed to have been first revealed by Albertus Magnus (c. 1193–1280) and it was apparently rediscovered by Robert Boyle in 1663, who also found that some diamonds will luminesce under pressure.
A ruby appears red because it absorbs all other colors of white light while reflecting red. A material which is mostly the same can exhibit different colors. For example, ruby and sapphire have the same primary chemical composition (both are corundum ) [ 38 ] but exhibit different colors because of impurities which absorb and reflect different ...
The Si-O-M linkage between the silicates and the metals are strong, polar-covalent bonds. Silicate anions ([SiO 2+n] 2n−) are invariably colorless, or when crushed to a fine powder, white. The colors of silicate minerals arise from the metal component, commonly iron.