The Amphibole Group is a collection of silicate minerals that are characterized by their double-chain silicate structure. These minerals typically contain elements such as silicon, oxygen, aluminum, iron, magnesium, and calcium. Amphiboles are commonly found in metamorphic and igneous rocks, contributing to their formation and properties. Amphiboles are known for their elongated crystal shapes and can appear in various colors, including green, brown, and black. Some well-known members of the Amphibole Group include hornblende and tremolite. These minerals are important in geology and can provide insights into the conditions under which rocks were formed.