Mineral Classification

In case you haven’t figured it out!

Minerals are classified by chemical composition 1. Minerals with the same anion or

anionic group have unmistakable family resemblances. For example, the carbonates resemble each other more closely than say the minerals of Cu.

2. They occur together in nature, for example, it is very common to find both calcite and dolomite in the same rocks.

3. It agrees with the naming of inorganic compounds in chemistry.

And at the next level Once minerals have been grouped by chemical composition, they can be further separated into groups on the basis of internal structure.

Native Elements Metals Semi Metals Non Metals

Sulfides Including sulfarsenides; arsenides and tellurides

Sulfosalts In these minerals, As and Sb play a role more akin to metals than anions. Many important Ag minerals are sulfosalts.

Oxides a) simple and multiple where O combines with one or metals (cations) Simple Multiple

b) hydroxides with OH- group and H2O molecules

Halides these minerals have Cl, Br, F, and I as anions

Carbonates Based on the carbonate radical

Hexagonal; orthorhombic; and monoclinic

You have examples of all three!

Nitrates NO3 radical Only 7 known minerals

Borates (BO3)-3 can form polymers--about 100 known minerals

So are they iso, meso, or aniso desmic?

Phosphates (PO4)-3 are usually hydrous as well

Sulfates (SO4)-2 can be hydrous or anhydrous

Tungstates (WO4)-2 scheelite and wolframite are both ore minerals for W

Silicates (SiO4) -4 The most important group of minerals!! Nesosilicates Sorosilicates Cyclosilicates Inosilicates Phyllosilicates Tectosilicates

Why can they form so many structures? Mesodesmic

Remember this term?

Nesosilicates

Sorosilicates

Cyclosilicates

Inosilicates

Phyllosilicates

Tectosilicates

What is the best way for you to remember formulas General formulas!! Next time