Calamine the zinc-impregnated gauze wrap used to treat ulcers of the leg in Unna boots. In a 1992 press release, the U.S. Food and Drug Administration announced that no proof had been submitted showing calamine to be safe for use or effective in treating bug bites, stings, and rashes from poison ivy, poison oak, and poison sumac. In a September 2, 2008 document, the U.S. Food and Drug Administration recommended applying topical over-the-counter skin protectants, such as calamine, to relieve the itch caused by poisonous plants such as poison ivy, poison oak, and poison sumac. Calamine Calamine, also known as calamine
Tantalum pentoxide tantalite are called coltan. Tantalite was discovered by Anders Gustaf Ekeberg at Ytterby, Sweden, and Kimoto, Finland. The minerals microlite and pyrochlore contain approximately 70% and 10% Ta, respectively. Tantalum ores often contain significant amounts of niobium, which is itself a valuable metal. As such, both metals are extracted so that they may be sold. The overall process is one of hydrometallurgy and begins with a leaching step; in which the ore is treated with hydrofluoric acid and sulfuric acid to produce water-soluble hydrogen fluorides, such as the heptafluorotantalate. This allows the metals to be separated from the various non-metallic