Traces of iron are responsible for the characteristic violet coloration of the quartz variety known as amethyst. However, how the geodes can grow to this size has remained a mystery. Most geodes ...
Citrine—the transparent, pale yellow to brownish orange variety of quartz—is rare in nature. In the days before modern gemology ... Since natural citrine is rare, most of the citrine on the market is ...
Ximen is a publicly listed company trading on the TSX Venture Exchange under the symbol XIM, in the USA under the symbol XXMMF, and in Frankfurt, Munich, and Berlin Stock Exchanges in Germany under ...