Topaz is a mineral that is used as a gemstone. It is a fluorine-containing and hydroxy-aluminum with the chemical formula AI2SiO4 nesosilicaat (OH, F) 2. Topaz has an orthorhombic crystal system. It crystallizes in a prismatic shape with a diamond-shaped ground plane. These prisms can reach a length of one meter. If the crystal faces have grooves, which is common, these gradients along with the longitudinal direction of the prism. Pure topaz is transparent and colorless, but by contaminants can occur in many different colors, especially straw yellow to brown, light blue or pink. Many get their topaz blue or pink color artificially by heating them. Mystic topaz (Mystic Topaz) variant is not a color, but a topaz which is coated with a thin film layer, creating a rainbow effect. Saxony was in the 18th century, a major supplier of (yellow) topazes: these so-called Saxon diamonds were mined in the Vogtland, where Schneckenstein was largely excavated. Topaz occurs in the sand fraction of Dutch Quaternary river sediments. Among others it is a characteristic element of sands of the northwest German rivers (eg precursors of the Weser). In the heavy-mineral analysis as in the Netherlands at the Geological Survey took place during the second half of the twentieth century, the mineral is assigned to the so-called stable group. The name of the stone can be traced back to the Greek.  Pliny the Elder carried the name back on a legendary island Topazius in the Red Sea, whose identity is uncertain, and the exact nature of the stones were it dismissed. The designation topaz gained its current meaning until after the Middle Ages. Topaz is one of the nine gems in Thailand Order of the Nine Gems. The Pope has a miter, called a mitra Preciosa with gold, topaz and pearls adorned. According to the Bible (Revelation 21: 19-20 KJV 1951) will be decorated the seventh foundation of the new city of Jerusalem to be with topaz. 19 And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper, the second sapphire, the third chalcedony, the fourth emerald, 20 the fifth onyx, the sixth carnelian, the seventh topaz, the eighth beryl, the ninth topaz, the tenth chrysoprase, the eleventh jacinth, and the twelfth amethyst .