Calamine the World Health Organization's List of Essential Medicines for being one of the most effective and safe medicines needed in a health system. Calamine is available over the counter as a generic medication. The wholesale cost in the developing world is about US$0.25–3.85 per 100-ml bottle. In the United Kingdom, it costs the National Health Service about £0.44. Calamine is used to treat itchiness. This includes from sunburn, insect bite, or other mild skin conditions. Calamine is mixed with either zinc oxide (ZnO) with about 0.5% ferric oxide (FeO) or a zinc carbonate compound. Calamine lotion is a component of
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