The several thousand minerals that are generally recognised are not a random scatter of different collections of elements, but occur in families or groups or series, within which they share many properties and exhibit an underlying logic. The way we define these groups , it has to be said, somewhat arbitrary: most attempts at classification are for we are forced to drawing boundaries to divide what is in many cases a continuum. There's also no single way of grouping minerals and although several eminent mineralogists have come up with classifications, there's no agreement about the way that is best. At the broadest level, however, it is useful to divide minerals inorganic minerals into two broad classes - the silicates and the non-silicates, and then to sub-divide these.
In this system:
silicates include all minerals in which the dominant component is silicate (silica + oxygen, typically in the form of one silicon atom attached to four oxygens),
non-silicates are all other inorganic mineral - i.e. those in which silica is generally lacking and in which other elements (ofdten in combination with oxygen) dominate.
Silicate minerals make up the majority of the minerals recognised by mineralogists, and account for most of the material in the Earth's crust. They are also more complex than non-silicates. Non-silicates, however, include many of the minerals considered to be of economic value, including many metals.
Each of these classes is then divided into groups, containing a more narrow range of minerals, usually distinguished in terms of their composition (chemistry) and internal structure.
In the case of silicates, the main groups are:
nesosilicates
sorosilicates
inosilicates
phyllosilicates
cyclosilicates
tectosilicates
In the case of non-silicates, it is useful to recognise seven groups, as follows:
native elements
oxides
carbonates
sulphides
sulphates
halides
phosphates
Both groups are outlined in the following pages (click the buttons to proceed):