Nonferrous Metals That Do Not Contain Iron Hematite

Obsidian obsidian is an extrusive igneous rock, a volcanic glass formed by rapid cooling.Its essential component is glass.Its accessory components are magnetite, ilmenite, oxides and other minerals, such as feldspar.It has the same composition as dacite or rhyolite, with less than 1 percent water.Its color is shiny black, with clear.