Alternating layers of albite with layers of one type of this mineral results in a silicate which exhibits a milky luster. That phenomenon, adularescence, is found in moonstone. As mafic magma cools, one type of this mineral progresses from being calcium-rich to sodium-rich on the right-hand continuous branch of Bowen's reaction series. That is the plagioclase variety of these minerals, which is of
Alternating layers of albite with layers of one type of this mineral results in a silicate which exhibits a milky luster. That phenomenon, adularescence, is found in moonstone. As mafic magma cools, one type of this mineral progresses from being calcium-rich to sodium-rich on the right-hand continuous branch of Bowen's reaction series. That is the plagioclase variety of these minerals, which is often found in granite along with quartz. For 10 points, name this class of tectosilicate minerals, the most abundant mineral group in the Earth's crust, whose orthoclase variety has a Mohs hardness of six.
Alternating layers of albite with layers of one type of this mineral results in a silicate which exhibits a milky luster.
{feldspar}s [accept {orthoclase} feldspars before “Bowen’s reaction series”]