Minerals PDF

EARTH SCIENCE LESSON 5: ROCK AND MINERALS 5.1.: MINERALS AND THEIR CHARACTERISTICS - DIFFERENT PROPERTIES OF MINERALS LEARNING OBJECTIVE At the end of the discussion, you should be able to: define and describe minerals; identify some rock-forming minerals using their physi...

EARTH SCIENCE LESSON 5: ROCK AND MINERALS 5.1.: MINERALS AND THEIR CHARACTERISTICS - DIFFERENT PROPERTIES OF MINERALS LEARNING OBJECTIVE At the end of the discussion, you should be able to: define and describe minerals; identify some rock-forming minerals using their physical and chemical properties; (S11-Ic-6) and describe and illustrate each rock- forming minerals using their physical and chemical properties. MINERALS MINERALS distinguished based on different physical and chemical properties Physical properties can be readily determined Chemical properties not readily determined MINERALS building blocks of rocks composed of one or more chemical elements with definite chemical composition Nature: solid, mostly inorganic CHARACTERISTICS OF MINERALS 1. naturally occurring – a product of Earth’s natural processes. 2. inorganic – it must be product of Earth’s physical processes. 3. homogeneous solid – minerals should have definite volume and rigid shape CHARACTERISTICS OF MINERALS 4. definite chemical composition – represented by a chemical formula. 5. orderly crystalline structure – atoms of minerals are arranged in an orderly and repeating pattern. PROPERTIES OF MINERALS To identify minerals, mineralogist observe the following properties: a. Color – mineral’s color may change depending on the surface. b. Streak – color of mineral in powdered form. c. Hardness – minerals resistance to scratching PROPERTIES OF MINERALS Mohs Scale of Hardness 10 – Diamond 9 – Corundum 8 – Topaz 7 – Quartz 6 – Orthoclase PROPERTIES OF MINERALS Mohs Scale of Hardness 5 – Apatite 4 – Fluorite 3 – Calcite 2 – Gypsum 1 – Talc PROPERTIES OF MINERALS d. Cleavage – mineral’s resistance to being broken and fracture. e. Crystalline structure or habit f. Diaphaneity/amount of transparency – ability to allow light to pass through it. This is affected by chemical makeup of the mineral sample. PROPERTIES OF MINERALS g. Luster – how light is reflected off a surface. h. Tenacity – describes the minerals reaction to stress. PROPERTIES OF MINERALS Brittleness – a mineral turns into powder Malleability – a mineral can be flattened by pounding with a hammer. Ductility – a mineral can be stretched into wire. Flexible but inelastic – minerals are bent but they remain in the new position. PROPERTIES OF MINERALS Flexible and elastic – minerals are bent, and they bring back to their original position. Sectility – ability of minerals to be sliced by a knife. MINERALS For example: DIAMOND hardest naturally-occurring mineral made up of a lattice of carbon molecules excellent insulator of electricity MINERALS For example: DIAMOND color; white to blue, pale yellow to colorless formed at high pressure not reactive to strong acids and strong bases MINERALS For example, CALCITE Calcium Carbonate (CaCO3) only common non-silicate rock-forming mineral brittle found in sedimentary and hydrothermal environments MINERALS For example, CALCITE color: generally white to colorless high reactivity with weak acids like vinegar vigorously reacts when diluted with hydrochloric acid MINERALS For example: QUARTZ complex silicate (SiO2) often referred to as framework silicate found in different kinds of rocks MINERALS For example: QUARTZ color: variable, but usually clear, white, milky white, purple, pink, brown inert and unreactive at room temperature very resistant to chemicals and heat MINERALS For example, BIOTITE member of the sheet silicates color: dark brown to greenish brown to blackish brown flexible but breakable needs optical, chemical, or x- ray analysis not very resistant to weathering MINERALS For example: GYPSUM water-soluble mineral sediment most common sulfate mineral color: clear, colorless, white, gray limited durability due to hardness soluble in hydrochloric acid SUMMARY MINERALS Building blocks, naturally-occurring Hardest natural mineral; not reactive Diamond to strong acids and strong bases Only non-silicate rock-forming Calcite mineral; reactive to weak acids. Complex silicate found in most kinds Quartz of rocks; unreactive to chemicals and heat at room temperature SUMMARY MINERALS Building blocks, naturally-occurring member of the sheet silicates; not Biotite very resistant to weathering. water-soluble mineral sediment; has Gypsum limited durability due to hardness and soluble in hydrochloric acid. MINERALS For example, TALC softest mineral; with soapy and greasy texture color: white, colorless, grey, or green resistant to heat, electricity, and chemicals not flammable MINERALS For example: OLIVINE member of the silicate family very susceptible to weathering almost as hard as quartz color: from translucent to olivine green to glassy MINERALS For example: OLIVINE important mineral in the Earth’s mantle with high crystallization temperature very resistant to chemicals MINERALS For example, CHLORITE also a sheet silicate like biotite color: generally in various shades of green with slight greasy texture produce a phantomed crystal MINERALS For example: GARNET commonly found in different kinds of rocks color: varies from red to reddish most are translucent MINERALS For example: GARNET Calcium garnets: low hardness, commonly green in color Manganese garnets: greater hardness, typically red in color SUMMARY MINERALS Building blocks, naturally-occurring softest mineral; Talc resistant to heat, electricity, and chemicals member of the silicate family; very Olivine susceptible to weathering sheet silicate; can produce a Chlorite phantomed crystal SUMMARY MINERALS Building blocks, naturally-occurring commonly found in the different kinds of rocks; Garnet Types: calcium garnets and manganese garnets