Mineral Groups Reference: Tarbuck and Lutgens Pages Minerals that form the rocks within Earth’s crust belong to seven (7) main mineral groups, which include: 1) Silicates 2) Carbonates 3) Sulfates 4) Oxides 5) Halides 6) Sulfides 7) Native Elements Nearly 4000 minerals have been discovered and named; however, no more than a few dozen are abundant. These few dozen makes up most of the rocks that comprise Earth’s crust. This is why we call them the rock-forming minerals.

Do You Remember? Do you remember the eight elements that make up more than 98 % of Earth’s crust (i.e. continental crust)? List them. Which two elements are most abundant in Earth’s crust? Oxygen and Silicon. Both comprise nearly three-fourths of Earth’s continental crust. Both elements combine to form the framework of the most common mineral group (i.e. the silicates). The framework is called the silicon-oxygen tetrahedron.

Hints To Classify Mineral Groups Olivine(Mg,Fe) 2 SiO 4 BariteBaSO 4 CalciteCaCO 3 Mineral groups that end with “ate” and have an oxygen group in its chemical formula are one of the following; Silicates = Si + Oxygen Sulfates = S + Oxygen Carbonates = C + Oxygen

Hints to Classify Mineral Groups Hematite Fe 2 O 3 PyriteFeS 2 Fluorite CaF 2 Mineral groups that end with “ide” and have a metal (e.g., Na, K) in its chemical formula are one of the following; Oxides = Metal + O Sulfides = Metal + S Halides = Metal + Cl, Br, F

Mineral Groups Silicates1)  A mineral group that has silicon and oxygen as part. of their atomic structure.  Comprise more than 96% of the crust (most common mineral group). Rock forming silicates are divided into two groups: Sialic Silicates (Aluminosilicates)  Rich in silicon and aluminum.  Comprise about 85% of the silicates in the crust.  Mineral are light in color. Examples include: Quartz Mica (Muscovite) Feldspar

Mineral Groups Silicates (Continued)1) Simatic Silicates  Rich in silicon and magnesium.  Comprise less than 15% of the silicates in the crust.  Minerals are dark in colour. Examples include: Olivine Pyroxene Amphibole

Mineral Groups Carbonates2)  compounds consisting of an atomic structure of one carbon and three oxygen (CO 3 ).  most common carbonate mineral is calcite (Ca CO 3 ), which makes up the chemcial sedimentary rock called limestone as well as the metamorphic rock called marble. Sulfates3)  compounds consisting of an atomic structure of one sulfur and four oxygen (SO 4 ).  the rock gypsum is an example of a sulfate and it also takes on the mineral name. (CaSO 4 2H 2 O)  The mineral barite (BaSO 4 ) is mined and used in drilling mud.

Mineral Groups Oxides4)  compounds consisting of an atomic structure of oxygen combined with one or more metals.  most common oxides are those of iron (Fe 2 O 3 ) and aluminum (Al 2 O 3 ); referred to as the Ore Minerals. As an example, the mineral hematite is Fe 2 O 3 Halides5)  compounds consisting of an atomic structure of chlorine or fluorine with sodium, potassium, or calcium.  Halite (NaCl) is the most common halide. It is often referred to as table salt.

Mineral Groups Sulfides6)  compounds consisting of an atomic structure of one or more metals combined with sulfur.  examples of minerals include: pyrite (FeS 2 ), galena (PbS), and sphalerite (ZnS). Native Minerals7)  elements that occur uncombined in nature.  commonly called native elements.  examples include: gold (Au), silver (Ag), copper (Cu), and sulfur (S).

NOTE Note that an ore mineral is any mineral that has enough of a particular element in it to be mined at a profit.

Sample Problem Which is an example of a halide? (A)barite (BaSO 4 ) (B)calcite (CaCO 3 ) (C)fluorite (CaF 2 ) (D)hematite (Fe 2 O 3 )