Zincite is a very rare mineral and its type locality is in Polandthe only source for stones of this size (the other source for grain-sized crystals is in New Jersey). The crystals were formed by by-product within the large smokestacks of a zinc smelting factory. Significant changes in temperature and air pressure inside the furnace created conditions supporting the spontaneous growth of these crystals in the chimneys. The supply of zincite from this source is long exhausted. The present oval-cut example is a particularly large one which is characterized by a brilliant tangerine orange hue and exceptional transparency.
Weighing approximately 46.45 carats and measuring 23.5 x 12.0 x 10.0mm