Tourmaline Crystal Gemstone MineralsByminerals
"Tourmaline" is the name given to a large group of boron silicate minerals that share the crystal structure and similar physical properties of a common area. But the chemical composition is quite different. Tourmaline is one of the most famous gemstones in the world and serves as a birthstone for the month of October. The name tourmaline comes from turamali.
Tourmaline is very abundant. Tourmaline is commonly found as an accessory mineral in volcanic and metamorphic rocks. Because tourmaline is weather-resistant, it accumulates in detritus deposits and is a common accessory mineral in sedimentary rocks.
The most important source of tourmaline in the United States is the tourmaline mines in Southern California. Tourmaline discoveries are being made in Afghanistan, Mozambique, Namibia, Nigeria, Pakistan, Tanzania, the United States, and other countries.