Calamine (mineral) Calamine (mineral) Calamine is a historic name for an ore of zinc. The name "calamine" was derived from "lapis calaminaris", a Latin corruption of Greek "cadmia (καδμία)", the old name for zinc ores in general. The name of the Belgian town of Kelmis, "La Calamine" in French, which was home to a zinc mine, comes from that. In the 18th and 19th centuries large ore mines could be found near the German village of Breinigerberg. During the early 19th century it was discovered that what had been thought to be one ore was actually two distinct minerals: Although chemically and
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