Many minerals separate into sheets. If the mineral has cleavage than it is common for it to separate into sheets. Mica separates into sheets.
The mineral that breaks into dark colored sheets is Biotite
Micaceous minerals, like biotite and muscovite have a platy cleavage.
Its Mica
Minerals take many shapes and have different levels of luster. Mica is a mineral that is very shiny and occurs in sheets.
cleavage
The mica group of minerals.
cleavage
Mica
Biotite is one of the mica group of silicate minerals.
Its Mica
Slate.
Mica is made up of sheets of silicate
Minerals take many shapes and have different levels of luster. Mica is a mineral that is very shiny and occurs in sheets.
Mica
Generally in books of thin sheets.
cleavage
The mica group of minerals.
cleavage
Mica is crystalline and forms layers.