Feldspar Georgia State University
Plagioclase Orthoclase Feldspar is a name given to a class of aluminum containing silicates which are sometimes called light silicates or nonferromagnesian silicates since they don t contain iron or magnesium The feldspars include orthoclase KAlSi 3 O 8 and plagioclase Ca Na AlSi 3 O 8 Note that the plagioclase differs from the orthoclase in terms of the