Final answer:
Mica is considered a complex silicate due to its sheet-like silicate tetrahedra structure within its mineral composition. It is a common mineral that forms under various conditions during metamorphism and contributes significantly to the composition of the Earth's crust.
Step-by-step explanation:
Is mica a complex silicate? Mica is indeed a member of the complex silicate mineral group. Silicates are minerals that contain silicon-oxygen bonds, and in the case of mica, these silicate tetrahedra are arranged in sheets.
Mica exhibits a range of composition and properties, but generally, they are characterized by their very thin layers, which can be peeled off in thin sheets. Mica falls into the category of silicate minerals with a complex structure due to the way its silicate components are layered at the molecular level, often resulting in uneven, flexible surfaces with a characteristic sheen.
Silicates are the most abundant minerals in the Earth's crust with about 90% being silicate material. Within this mineral class, the sheets of mica can be found commonly interspersed with other minerals like quartz and feldspar. Minerals such as chlorite, biotite, and muscovite are all part of the mica family, each being formed under different pressure and temperature conditions during the process of metamorphism. These variations help geologists determine the geological history and conditions of the earth's crust where these minerals are found.