Description
Topaz is a mineral used as a gemstone. It is a hydroxyl and fluorine-containing aluminum nesosilicate with the chemical formula Al2SiO4(OH,F)2. Topaz has an orthorhombic crystal system. It crystallizes in a prismatic form with a rhombic base. These prisms can reach a length of one meter. If the crystal faces have grooves, which is common, these run along the length of the prism. Pure topaz is transparent and colorless, but due to impurities, it can appear in many different colors, primarily straw yellow to brown, light blue, or pink. Many topazes get their blue or pink color artificially by heating them. Mystic topaz is not a color variety, but a topaz coated with a thin film, creating a rainbow effect. In the 18th century, Saxony was an important supplier of (yellow) topazes: these so-called Saxon diamonds were mined in the Vogtland, where the Schneckenstein was largely excavated. Topaz occurs in the sand fraction of Dutch Quaternary river sediments. It is, among other things, a characteristic element of sands from northwest German rivers (for example, the precursors of the Weser). In the heavy mineral analysis conducted in the Netherlands by the National Geological Survey during the second half of the twentieth century, the mineral is classified in the so-called stable group. The name of the stone can be traced back to Greek.[4] Pliny the Elder traced the name back to a legendary island of Topazius in the Red Sea, whose identity is uncertain, as is the precise nature of the stones that came from it. The term topaz only acquired its current meaning after the Middle Ages. The topaz is one of the nine gemstones in the Thai Order of the Nine Gems. The Pope owns a miter, a so-called mitra preciosa, which is adorned with gold, topazes, and pearls. According to the Bible (Revelation 21:19-20 NKJV), the seventh foundation of the new city Jerusalem will be adorned with topazes. 19 And the foundations of the wall of the city were adorned with every precious stone: the first foundation was a diamond, the second a sapphire, the third a ruby, the fourth an emerald, 20 the fifth an sardonyx, the sixth a sardius, the seventh a topaz, the eighth a beryl, the ninth a chrysolite, the tenth a chrysoprase, the eleventh a sapphire, and the twelfth amethyst.
