The six families we will investigate include
the sulfides, sulfates, oxides, halides, carbonates, borates, and
silicates. Sulfides and sulfates all have sulfur in the anion.
For example galena is a sulfide and its composition is PbS. The sulfides
mainly are metallic. The sulfates include the radical SO4 and
include minerals that are nonmetallic. These can include gypsum.
Some families have an anion that is related to
oxygen. Oxides contain a anion that is usually a metal in combination
with oxygen. For example, hematite is iron plus oxygen (Fe2O3).
Carbonates include the CO3 radical and includes minerals like
calcite. Borates contain the BO3 group and include minerals
like borax and ulexite. Sulfates also have oxygen within its radical.
Silicates form the largest chemical class among
the minerals. They contain various elements in different combination
like sodium, potassium, calcium, magnesium, aluminum, and iron in
combination with silicon and oxygen. They have very complex chemical
Galena - a sulfide