Bellringer Organize the minerals on your table into

Bellringer: Organize the minerals on your table into the groups that you think they belong

Mineral Groups • Silicates –These make up more than 90 percent of the minerals in Earth’s crust • Carbonates • Oxides and Sulfides

Silicates • A compound of silicon, oxygen, usually one or more other metallic elements • The basic building block is the silica tetrahedron

Quartz • Chemical formula: Si. O 2 – It is made up of a continuous framework of Si. O 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula Si. O 2 – *Min Book • Most sands consist mainly of grains of quartz Why would this be?

Feldspars • The feldspar family makes up about 60% of Earth’s crust • All feldspars have: – 2 directions of cleavage – Hardness of 6 – Pearly luster • The 2 major groups of feldspars are: – Orthoclase feldspar – Plagioclase feldspar

The 2 Feldspars • Orthoclase – Potassium Feldspar • Color is light pink or salmon • Plagioclase – Sodium or Calcium Feldspar • Color ranges from white to gray • Examples include: – Albite – Labradorite • Feldspars are used in everyday products like glass and ceramics

Other Silicates • Pyroxenes – Augite • Most common pyroxene • Is a Ferromagnesian silicate and is always dark in color • Micas – Most common are Biotite and Muscovite – Both have a hardness of 2. 5 and 1 cleavage plane • Muscovite is silvery white color • Biotite is dark brown or black color

Other Silicates Cont. • Amphiboles – Hornblende is the most common – Hardness of 5 -6 – Color ranges from dark green, brown, or black • Olivines – Color is olive-green • Kaolinites – Kaolin • Resembles clay • Color of white

Carbonates • A carbonate is a mineral made of negatively charged carbonate ions bonded to positive metal ions Where have we heard of carbonates before and where can we find them around here?

Carbonates Cont. • Calcite – Also called calcium carbonate – Most common carbonate mineral – Color ranges from colorless to white – Hardness of 3 – Breaks into flat sided rhombahedra – Also fizzes when diluted HCl is droppped on it

Carbonates Cont. • Dolomite – Also called magnesium carbonate – Like calcite it will also break into flat sided rhombahedra – Will not fizz or react strongly when HCl is dropped on it due to the magnesium in its chemical formula • Calcite = Ca. CO 3 and Dolomite = Ca. Mg(CO 3)2

Oxides and Sulfides • An Oxide is a mineral consisting of a metal element combined with oxygen • A Sulfide is a mineral consisting of a metal element combined with a sulfur • Not as common as silicates or carbonates • They contain significant amounts of iron • Important economic resources

Oxides • Hematite – Most common iron oxide – Color is usually red – It can have a metallic luster – Always will streak reddish brown!!! • Magnetite – Color is usually black – Shiny to dull luster – Unique property = Its MAGNETIC

Sulfides • Pyrite – Most common sulfide mineral – It is an iron sulfide • Chemical formula is Fe. S 2 – Color ranges from pale brass to golden yellow – Hardness of about 6 – Also known as “Fool’s Gold”