Chemistry Reference
In-Depth Information
TABLE 4
Chemical Classification of Minerals
Class
Compositional characteristic
Examples
Native
Single element
Native metals, native nonmetals
elements
Oxides
Metal ion(s) + oxygen ion
Haematite (composed of iron oxide), a
red pigment and an iron ore
Corundum (composed of aluminum
oxide), an abrasive silica (composed
of silicon dioxide), common sand
Sulfides
Metal ion(s) + sulfur ion
Galena (composed of lead sulfide), a
metal ore, from which lead and also
silver (which occurs in galena as an
impurity, are extracted
Pyrite (composed of iron sulfide), an
iron ore
Halides
Metal ion(s) + halogen ion
Common salt (sodium chloride), a
component of animal diets
Fluorite (calcium fluoride), a lapidary
material and flux
Carbonates
Metal ion(s) + carbonate
Calcite (calcium carbonate), used for
ion
making lime, a building material
Marble (calcium carbonate), building and
lapidary stone
Sulfates
Metal ion(s) + sulfate
Gypsum (calcium sulfate), raw material
ion(s)
for making plaster of Paris
Alabaster (calcium sulfate or calcium
carbonate), a lapidary material
Silicates
Metal ion(s) + silicate ion
Granite (a metal silicate), used mostly
for building
The (compositionally) simplest mineral class comprises the native
elements, that is, those elements, either metals or nonmetals that occur
naturally in the
native state
, uncombined with others. Native gold, silver, and
copper, for example, are metals that naturally occur in a ductile and mal-
leable condition, while carbon - in the form of either graphite or diamond -
and sulfur are examples of nonmetallic native elements. Next in composi-
tional complexity are the
binary minerals
composed of two elements: a metal
or nonmetallic element combined with oxygen in the
oxides
, with a halogen
- either fluorine, chlorine bromine, or iodine - in the
halides
, or sulfur, in the
sulfides
. The oxide minerals, for example, are solids that occur either in a
somewhat hard, dense, and compact form in mineral ores and in rocks, or
as relatively soft, unconsolidated sediments that melt at moderate to
