Download Rock forming minerals

• identify common rock forming minerals
 The
geology of a given area, particularly
the rocks and minerals, plays a large role
in the local environment.
 Rocks and minerals break down to form
soils.
 The minerals and nutrients in a particular
soil influences what sorts of plants and
therefore animals will occur in an area.
 Most
rocks are formed from one or more
minerals.
 Minerals are inorganic substances with
specific physical and chemical
properties.
 Minerals can be used to identify rocks
and soils.
 Approximately
95% of minerals are silicates
which contain silicon (Si) and oxygen (O)
atoms bonded together. Oxygen (46%) and
silicon (28%) are the two most abundant
elements in the Earth’s crust.
 Carbonates contain CO3 molecules.
 Sulfates contain S04 molecules, sulfides
contain elemental sulfur (S).
 Oxides of iron and aluminium are relatively
common, e.g. haematite.
 Hardness: is
the ability to resist
scratching. Diamond has a hardness of
10, talc has a hardness of 1 (Moh’s scale
of hardness).
 Lustre: describes the way a mineral
reflects light, e.g. dull, vitreous (shiny)
 Colour: some minerals (e.g. quartz) can
be variable in colour, however some
minerals (e.g. olivine) can have
consistent colour
 Cleavage: refers
to how a mineral
naturally breaks or splits. Cleavage can
occur in one, two or three planes (see fig.
3.2.4, p. 132).
 Density: is the objects mass divided by
it’s volume, usually in g/cm3.
 Texture: refers to the size of crystals in a
mineral, small crystals will feel smooth,
larger crystals will usually feel rough.
 Email
or submit by 9am Monday 7/2/11
 Questions 1,3,4,8 on p. 131.
 Questions 1,2,3,5,6,9 on p. 133.