- from Rocks and Minerals
900L - 1040L
Minerals are the building blocks of rock.
Some rocks are made of a single type of mineral. But most are made of a few types joined together. Altogether there are about 4,000 types of minerals. Every mineral has its own chemical composition and properties, such as what temperature it melts at, how hard it is, what color it is, and how lustrous (shiny) it is.