Minerals are objects of great beauty and value to many. All minerals, both those treasured as gemstones and those used industrially, are found in the rocks of the Earth. The author tells how these rocks, some up to 3,500 million years old, came to be composed of minerals which are naturally occurring compounds of the chemical elements. Some rocks consist of one mineral, but most are aggregates of a number of minerals. He explains how the type of rock indicates the origin of the minerals it contains. Most of the book is devoted to a survey of the minerals themselves, which are grouped in the accepted chemical sequence. The chemical formula of a mineral is given, as are its chemical properties, and aids to its identification - so important to those building a mineral collection. A remarkable amount of information is clearly outlined on the most common minerals and some that are less common. The selection ranges from native elements like gold, platinum, silver, diamond and graphite to Pho