Topaz on parent rock sourced from Kunar, Afghanistan Super show piece.

Topaz is a mineral that is used as a gemstone. It is a hydroxy- and fluorine-containing aluminum nesosilicate with the chemical formula AI2SiO4 (OH, F) 2. Topaz has an orthorhombic crystal system. It crystallizes in a prismatic shape with a diamond-shaped base. These prisms can reach a length of one meter. If the crystal faces have grooves, which is common, they run along the longitudinal direction of the prism. Pure topaz is transparent and colorless, but due to contamination it can appear in many different colors, especially 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 variant, but a topaz that is coated with a thin film layer, 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. Among other things, it is a characteristic element of sands of the northwestern German rivers (for example, predecessors of the Weser). In the heavy mineral analysis as it took place in the Netherlands at 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 to a legendary island of Topazius in the Red Sea, the identity of which is uncertain, as is the exact nature of the stones that came from it. The term topaz only got 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 decorated with gold, topazes and pearls. According to the bible (Revelation 21: 19-20 NBG translation 1951) the seventh foundation of the new city Jerusalem will be decorated with topaz. 19 And the foundations of the wall of the city were decorated with all kinds of precious stones. The first foundation was diamond, the second lazur, the third ruby, the fourth emerald, the fifth sardonyx, the sixth sardius, the seventh topaz, the eighth beryl, the ninth chrysolite, the tenth chrysoprase, the eleventh sapphire, the twelfth amethyst .