Please te that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Hephaestus Books represents a new publishing paradigm, allowing disparate content sources to be curated into cohesive, relevant, and informative books. To date, this content has been curated from Wikipedia articles and images under Creative Commons licensing, although as Hephaestus Books continues to increase in scope and dimension, more licensed and public domain content is being added. We believe books such as this represent a new and exciting lexicon in the sharing of human kwledge. This particular book contains chapters focused on Cadmium compounds, and Cadmium minerals. More info: Cadmium is a chemical element with the symbol Cd and atomic number 48. The soft, bluish-white metal is chemically similar to the two other metals in group 12, zinc and mercury. Similar to zinc it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low melting point compared to transition metals. Cadmium and its congeners are t considered transition metals, in that they do t have partly filled d or f electron shells in the elemental or common oxidation states. Average concentration in the earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate.