What is the prime characteristic that geologists use to separate minerals into classes?

A mineral is a naturally occurring,inorganic, crystalline substance that aggregate to form rocks. Geologists separate minerals into classes based on their chemical composition. The different classes of minerals include halides, oxides, phosphates and sillicates.  Rocks are usually classified based on the grouping and composition of minerals in rocks. 

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].

Summer months are the wettest.