1. Minerals

2. Building Blocks of Matter
An element is a substance that cannot be broken down into simpler substances by chemical or physical means
The basic unit of matter is the atom (smallest particle of matter that retains characteristics of an element)
Atoms are made of subatomic particles: protons (+), electrons (-), and neutrons
Protons (atomic number) and neutrons reside in the nucleus
Electrons move around in energy levels outside of the nucleus

3. Building Blocks of Matter

4. Building Blocks of Matter
Atoms of the same element but with different neutrons are isotopes
Carbon-12, Carbon-13, Radioactive Carbon- 14

5. Building Blocks of Matter
Two or more elements can combine to form compounds (H2O)
Properties of compound differ from the elements
Ionic bonds form between positive and negative ions (element loses or gains electron)
Covalent bonds involve sharing of electrons between elements (H2O)
Metallic bonds form when electrons are shared by metal ions

6. Building Blocks of Matter

7. Minerals
Mineral is a naturally occurring, inorganic solid, with an orderly crystalline structure and a definite chemical composition
Natural, not man-made (synthetic)
Solid at normal Earth temperatures
Crystalline- atoms or ions are arranged in orderly repetitive manner
Consistent element (gold) or chemical compound (quartz [SiO2])
Inorganic

8. How Minerals Form Crystallization from magma as it cools
Precipitation occurs when water evaporates leaving the dissolved substances can react to form minerals
Changes in pressure and temperature can cause atoms to rearrange
Hydrothermal solution (water and dissolved substances between 100C-300C) form new mineral when come in contact with mineral

9. Mineral Groups Minerals are classified based on their composition
Silicates are composed primarily of silicon and oxygen
Make up 95% of all minerals on Earth
Ferromagnesian minerals contain a lot of the elements iron and magnesium (usually dark in color)
Nonferromagnesium silicates are usually light in color because they don’t contain iron and magnesium

10. Mineral Groups Sulfides have compounds combined with sulfur
Galena (PbS), sphalerite (ZnS)
Carbonates have compounds made up of a carbon atom and bordered by oxygen
Halides contain elements that combine with halogen ion (chlorine, fluorine, bromine, iodine)
Salt is a halide mineral called halite

11. Mineral Groups
Sulfates contain compounds made of sulfur enclosed by four oxygen atoms (CaSO4)
Oxides contain element combined with oxygen
Hematite (rust)
Native elements are elements in relatively pure form
Gold (Au), Copper (Cu)

12. Properties of Minerals
Mineral’s properties can help identify them
Hardness is a mineral’s resistance to scratching
Moh’s hardness scale ranges from 1-10
10 is diamond, talc is 1

13. Cleavage
Cleavage is the breakage along planes of weakness (based on atomic arrangements)
One direction: mica breaks into sheets because bond holding sheets together is weak
Two directions: feldspar breaks into two directions at about 90 degrees
Three directions: calcite, 75 degrees

14. Fracture and Streak
Fracture occurs when minerals don’t show cleavage when broken
Break along curved surfaces, splinter, or just break unevenly
Streak is the color of the mineral in its powdered form
Created by rubbing mineral across streak plate
More reliable than color of mineral (small amounts of different elements can change color of mineral)

15. Color
Sapphires have different colors based on small amounts of different elements

16. Luster and Crystal Form
Luster describes how light is reflected from the surface of a mineral
Metallic luster- have metallic appearance
Glassy- quartz; earthy- chalk
Crystal form is the visible expression of a mineral’s internal arrangement of atoms
If allowed to form slowly and without space restrictions they form consistent crystal shape

17. Density and Acid Test
Density is the ratio of an object’s mass to its volume (D=m/V)
Density of a pure mineral is a constant value
Adding dilute HCl to an unknown mineral is the acid test
If the sample fizzes, it is a carbonate
The fizz is carbon dioxide