Atoms to Minerals MATTER: "anything that has mass and volume" 3 Phases Solid / Liquid /Gas Elements: can not be separated naturally into smaller parts C carbon N nitrogen O Oxygen Compounds: a chemical substance formed from 2 or more elements. Water (H2O) Halite (NaCl) Chemical Formulas Calcite (CaCo3) An atom contains an electron cloud surrounding a nucleus composed of a proton and neutron. Electrons have a (e-) charge Protons have a (+) charge Neutrons have a (Ø) neutral charge The number of Protons is equal to the number of Electrons. The atomic number = The number of protons in a nucleus. It determines the chemical properties of an element The mass number= Number of protons + number of neutrons Covalent “Sharing” Bonds Ionic “Borrowing” Bonds Before After There are seven orbital paths that an electron can travel in. The 1 st orbital path can only hold two electrons. The 2nd can hold 8 e' The 3rd can hold 18e' The 4th can hold 32 e' The 5th can hold 21 e' The 6th can hold 9 e The 7th can hold 2 e' Mineral formation Most minerals crystallize from MAGMA or LAVA, Molten material is a liquid mixture of freely moving crystals. As molten material cools crystalline solids form. Water can also produce minerals by evaporation and chemical precipitation. The type of mineral formed depends on two factors. 1. Types of element in the magma…. 2. The melting point of each mineral…. Minerals with high melting point will crystallize first. Slow cooling promotes large crystals Fast cooling promotes fine grained or small crystals Minerals and Rocks A. Minerals "The building blocks of rocks” 1. Defined as… a. Naturally Occurring b. Crystal Structure c. Inorganic (nonliving) d. Have a specific internal arrangement of atoms 2. Chemical composition of Minerals a. can be a single element ex. (Au) Gold (Ag) Silver b. can be a compound ex. Calcite CaCo3 3. Rocks can be… a. Polyminerallic: Composed of two or more minerals ex. Granite Mica Quartz Feldspar b. Monominerallic: Composed of one mineral ex. Quartzite Quartz B . Minerals can be identified on physical or chemical properties “Determined by their specific arrangement of atoms.” 1. Physical Characteristics a. Color b. Streak c. Hardness d. Luster a. e. Cleavage f. Specific Gravity g. Crystal Structure Color "outside color of mineral" Impurities discolor a mineral b. Streak "powdered form of mineral true color" streak or no streak c. Hardness "Scratch Test" Used to Identify minerals by the process of elimination. Moh's Scale of Hardness http://www.gwydir.demon.co.uk/jo/minerals/hardness.htm d. Luster: Looks like a metal or not. Metallic Non-Metallic (glassy, pearly, earthy) e. Crystal Structure: Minerals that grow in ideal conditions have a crystalline shape that is determined by their I.A.A.’s Silicon Tetrahedron Silicon = Oxygen = Atoms Geometric Figure w/ 4 faces. Silicon at the center oxygen on the corners. Crystals with Tetrahedrons are called Silicates. http://www.usd.edu/esci/figures/BluePlanet.html 3. ESRT Common Minerals & Elements Most abounded elements in the lithosphere -Oxygen -Silicon Combine to form chains or sheets. F. Cleavage: Mineral will split along a flat surface of weakness. - Due to internal arrangement of atoms. Halite Mica Conchoidal Fracture: Breaks into a chunk. Opal Quartz g. Specific Gravity (Density) -Arrangement of atoms and packing determines the density 2. Chemical & Special Properties a. Acid Test: Minerals Bubble (Calcite) b. Taste (Halite) c. Double Refraction: (Calcite) d. Magnetism (Magnetite) Summery The Chemical and Physical Properties of a mineral are determined by the internal arrangement of atoms.