2.  There are nearly 4000 minerals identified in the Earth’s crust.  Each has an unique chemical composition and internal crystalline structure.  Some rare and some very common

3.  Elements are the building blocks of minerals.  Most minerals contain more than one element.  There are some with only one element.  There are 113 known elements,  but only 92 occur naturally  The rest have been created in the laboratory

4.  Elements are composed of atoms.  An atom of an element is the smallest particle that retains the characteristics of the element.  If the atom is broken apart the resulting characteristics of the element are no longer present.

5.  Atoms are composed of:  A nucleus which contains:  Neutrons – neutral charged particles  Protons – positive charged particles  Electrons  Which have a negative charge  Orbit the nucleus in energy levels, shells

6.  The number of neutrons of an atom can vary without changing the characteristics of the atom.  The variations in the number of neutrons of a particular element are called Isotopes.  Some elements are stable.  The majority of elements however are unstable, which leads to combining or bonding with other elements.  This bonding leads to three-dimensional crystals called minerals

7.  When elements combine it is achieved by:  Covalent bonding – where electrons of combining elements are shared.  Ionic Bonding – where electrons are taken/given away

8.  The bonding of elements is what gives the characteristics of the new material formed  This will determine it behaviour  It shape or crystalline structure.  Example: Halite ( NaCl )  Sodium is a soft, silvery, potentially explosive metal  Chlorine is a green toxic gas  Together they make table salt  Which has a cubic structure  Examine table salt and you will see this structure

9.  Of the 92 naturally-occurring elements only 8 make up 98% of the Earth’s crust

10.  The majority of minerals contain a combination of these 8 elements.  The most popular combination involves Oxygen and Silicon  This combination is known as a Silicate, SiO 2  The silicon-oxygen bond forms a tetrahedron crystal, which is a four sided pyramid

11.  Minerals containing the silicon-oxygen tetrahedron are the most common group of the mineral on Earth.  This group includes about 1/3 of all minerals in the Earth’s crust.  Geologist classify minerals into various groups.  Minerals within the same group have similar characteristics

12.  Silicates – silicon oxygen  Elements – un-combined elements  Carbonates – contain a metal and the carbonate ion ( CO 3 -2 )  Oxides – contain a metal and oxygen  Sulphides – contain a metal and sulphur  Sulphates – contain a metal and the sulphate ion ( SO 4 -2 )  Halides – contain a metal and either chlorine, fluorine, iodine or bromine