1. MINERALS They’re not only in your breakfast cereal.

2. What is a mineral? A mineral is typically a compound consisting of more than one element. Ex. Halite (NaCl) There are minerals that consist of only one element. Ex. Graphite (C)

3. Characteristics of a mineral Naturally occurring Inorganic Solid Has a definite chemical composition. Has a crystalline structure. (an orderly internal arrangement of atoms.

4. A crystal is composed of a structural unit that is repeated in three dimensions. This is the basic structural unit of a crystal of sodium chloride, the mineral halite.

5. Minerals have distinctive physical and chemical properties that allow for their identification.

6. Hardness Resistance to being scratched. Controlled by the strength of bonds between atoms Comparative identification with Moh’s scale.

8. Cleavage The tendency of a mineral to break along zones of weakness to form smooth planes.

9. Fracture A mineral that lacks zones of weakness will exhibit uneven breaking surfaces.

10. Streak Color of a mineral when it is powdered This characteristic is usually very consistent.

11. Luster The way a mineral’s surface reflects light Two groups: metallic and non-metallic.

12. Color The most obvious but often the least useful. Because: The same mineral can be different colors. Different minerals can be the same color.

14. Special Properties of Minerals Carbonates react with dilute HCl and other acids by fizzing or bubbling (releasing CO2 gas)

15. Special Characteristics - Fluorescence Some minerals will glow when placed under short-wave or long-wave ultraviolet rays Franklin and Ogdensburg NJ are famous for their fluorescent minerals

16. Special Characteristics - Salty Taste DO NOT TASTE MOST MINERALS! Halite is the exception - it will taste salty

17. The Crystal Cave of Giants was accidentally discovered in 2000 by miners working in the silver and lead mine at Naica, Mexico. It lies almost 300 meters (900 feet) below the surface of the Earth and it contains the largest crystals known in the world

18. Special Characteristics - Magnetism Many iron minerals will produce an invisible magnetic force field “Lodestone” was used by Vikings more than 1,000 years ago as compasses