Unit 2 Rocks: Note 1 Minerals

Defining Minerals: 4 Characteristics a material needs to be a mineral

1. Naturally Occurring: must exist in nature, or produced by a natural geologic feature

2. Inorganic: cannot have both C and H together, only one or the other, or neither

3. Ordered and Crystalline: must be made of a symmetrical arrangement of atoms, and must be solid at some temperature found on Earth

4. Specific Chemical Makeup: must have a chemical formula that involves all major elements present in the mineral

Mineral Bonding: Chemical bonding affects mineral types, 4 kinds of bonding

1. Ionic: Transfer of electrons (NaCl, table salt)

2. Covalent: Sharing of electrons, to fulfill shells, strong (Carbon)

3. Metallic: electrostatic electrons, all electrons are shared, strong, creates a matrix of electrons that is good fro transferring electrons (electricity)

4. Van Der Waal: temporary dipole attracts, weak, a type of electrostatic attraction (Graphite)

Mineral Physical Characteristics

1. Color: determined by the minority elements in the crystalline lattice, making it possible for one mineral to have multiple colors. For example, Quartz can be purple, pink, and white

2. Streak: determined by dragging a mineral across a ceramic, leaving a black or white streak. If not streak is produced the mineral is harder than the ceramic

3. Luster: determined by how the mineral reflects light off of its surface. Metallic is shiny, non-metallic is not shiny

4. Hardness: determined by the Mon hardness scale, from 1 the weakest to 10 the strongest. 1 is very soft (talk), 10 is very hard (diamond), the scale is exponential increasing by an order of 10 \

5. Cleavage: determined by what the shape of the mineral is after it breaks.

   1. Cleavage Planes: determined by the minerals lattice structure, broken along the weak bonds. They are parallel, flat surfaces

   2. Cleavage Direction: each distinct direction that is found after breaking that must be parallel, is accounted as a cleavage direction. There are 0-4 sets of direction, the more weak bonds arranged in a row, the more directions

   3. Fracturing: if there is no parallel breaking

6. Specific Gravity: determined by how dense the material is, controlled by the elements its made of (m/unit volume)

7. Other classifications: magnetism, double refraction, taste, smell, acid reaction

• Minerals are the building blocks of rocks

• Rare minerals are commonly found in the Earth’s crust, but hard to extract and refine

• Rock Cycle: