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
Metallic mean Metallic mean The metallic means or silver means (also ratios or constants) of the successive natural numbers are the continued fractions:formula_1 The golden ratio (1.618...) is the metallic mean between 1 and 2, while the silver ratio (2.414...) is the metallic mean between 2 and 3. The term "bronze ratio" (3.303...), or terms using other names of metals (such as copper or nickel), are occasionally used to name subsequent metallic means. The values of the first ten metallic means are shown at right. Notice that each metallic mean is a root of the simple quadratic equation: formula_2, where formula_3 is