Blue Garnets And Metamorphism

264 Words2 Pages
According to geology.com, Garnets are minerals are in metamorphic, igneous, and sedimentary rocks. Most garnet forms at convergent plate boundaries where shale is being acted upon by regional metamorphism. The heat and pressure of metamorphism breaks chemical bonds and causes minerals to recrystallize into structures that are stable under the new temperature-pressure environment. As these rocks are metamorphosed, the garnets start as tiny grains and enlarge slowly over time as metamorphism progresses. As they grow, they displace, replace, and include the surrounding rock materials. (http://geology.com/minerals/garnet.shtml, n.d.)
Garnets are typically red in color. Blue garnets are extremely rare. Its streak is colorless, its luster is vitreous.