MineralsGroup4

__**What are minerals?**__ minerals are naturally occurring inorganic solid, with a specific chemical compostion and a definite crystalline structure.

__**Characteristics of a Mineral**__ 1. Inorganic 2. Naturally Occuring 3. Definite Crystaline Structure 4. Solids with Specific Characterization

__**Chemical Properties of a Mineral**__

__**Mineral Families**__ 1. Silicates- Minerals that contain oxygen and silicon. 2. Sulfides- Compounds of sulfur and one or more elements. 3. Oxides- Compounds of oxygen and metal. 4. Sulfates-Minerals that are composed of elements with the sulfate ion SO 5. Halides- Minerals made up of chloride or fluoride along with calcium, sodium, or potassium. 6. Carbonates- Minerals composed of one or moremetallic eliment and CO3² . __**Physical Properties of Minerals**__ 1. Hardness-measure of how easily a mineral can be scratched. 2. Luster-the way a mineral reflects light from its surface. 3. Color-sometimes caused by the presence of trace elements or compounds within a mineral. 4. Streak- the color of a mineral when its broken up and powdered. 5. Cleavage-mineral that spilts relatively easily and evenly along one or more flat planes. 6. Fracture-minerals that break with rough or jagged edges. 7. Magnetism 8. Specific Gravity 9. Crystal System 10. Transparency

__**Special properties**__ 1. Double Refraction occurs when a ray of light passes through the mineral and is split into two rays. 2. Effervescence occurs when hyrochloric acid causes calcite to fizz. 3. Magnetism occurs between minerals that contain iron; only magnetite and pyrrhotite are strongly magnetic. 4. Iridescence- a play of colors, caused by the bending of light rays. 5. Fluorescence occurs when some minerals are exposed to ultraviolet light, which causes them to glow in the dark.