👉 Feldspathoidal is a type of mineral that consists of two layers, each containing a different mineral. The first layer is known as the feldspar and consists of calcite (CaCO3) and quartz (SiO2). The second layer is known as the amphibole and consists of mica (MgAl2Si2O8) and talc (Na2CO3). Feldspathoids are used in a variety of applications, including glass-making, ceramics,
