1. Minerals & Their Families
Chapter 3

2. What is a Mineral? Are the building blocks of the Earth’s crust!
Naturally occurring: found everywhere in nature
Inorganic: made of non-living things
Solid: state of matter which is hard and breakable
Definite chemical composition: made of specific elements which makes them unique from each other
Crystalline structure: atoms are arranged in a pattern which creates crystals

3. Elementally Speaking Most minerals are made of 2 or more elements
8 elements are in greatest abundance in the Earth’s crust, with silicon and oxygen found in most minerals
8 abundant elements are:
Silicon (Si)
Oxygen (O)
Aluminum (Al)
Iron (Fe)
Calcium (Ca)
Sodium (Na)
Potassium (K)
Magnesium (Mg)

4. All in the Family
When studying the chemical formulas for minerals, we look at 3 different groups: silicates, non-silicates, and native elements
Silicates are the largest group and native elements are the smallest group

5. The Silicates
Rose Quartz
Also called the “rock formers” because they make up most of the rocks that we see
All members of this family contain SILICON and OXYGEN (SiO)
Most common members are quartz (SiO2) and feldspar (KAlSi3O8)
Feldspar

6. Non-Silicates
This family contains anything that is NOT a silicate, with no SiO ion in its chemical formula
Chemical formula is expressed as a METAL + ION
Broken down into 4 sub-families: carbonates, oxides, sulfates, and sulfides
Magnetite

7. Carbonates and Oxides
In members of the carbonate family, you are looking for the CO3 ion
An example is the mineral calcite, which is CaCO3
Members of the oxide family have a metal + oxygen ion as its chemical formula
An example is the mineral hematite, which is Fe2O3
Calcite
Hematite

8. Sulfates and Sulfides
In the sulfate family, you are looking for the SO4 ion
An example is the mineral olivine, which is Fe2SO4
In the sulfide family, you are looking for a metal + sulfur ion
An example is the mineral galena, which is PbS
Olivine
Galena

9. Native Elements This is the smallest group of elements
Consists of elements that exist by themselves in nature
Examples are gold (Au), silver (Ag), copper (Cu), and diamond (C)
Copper

10. Crystallography….What is it?
Mineralogists study the arrangement of the interlocking crystals in minerals
Crystals are created because of the repeating pattern of atoms
6 main crystal shapes: cubic, tetragonal, hexagonal, orthorhombic, monoclinic, and triclinic