Chapter 3 Minerals

I. Minerals A. Review Vocabulary: Atoms  tiny particles that make up matter; composed of protons, electrons, and neutrons.

I. Minerals B. Mineral → a naturally occurring, inorganic solid that has a definite chemical composition and an orderly internal atomic structure.

C. Look at the five parts to the definition: 1 C. Look at the five parts to the definition: 1. Naturally Occuring = made by nature; not man-made.

C. Look at the five parts to the definition: 2 C. Look at the five parts to the definition: 2. Inorganic = is not living, never was living, and was not made by life processes.

C. Look at the five parts to the definition: 3 C. Look at the five parts to the definition: 3. Solid = not a liquid or gas.

C. Look at the five parts to the definition: 4 C. Look at the five parts to the definition: 4. Definite Chemical Composition = the specific elements that make up the mineral. NaAl(SiO3)2

C. Look at the five parts to the definition: 5 C. Look at the five parts to the definition: 5. Orderly Arrangement of Atoms = the atoms are arranged in a repeating pattern.

D. The word crystalline means that atoms are arranged in a pattern that is repeated over and over again.

Crystal → a solid in which the atoms are arranged in an orderly, repeating pattern.

There are 6 basic crystal shapes: Hexagonal 4. Orthorhombic Tetragonal 5. Monoclinic 3. Cubic 6. Triclinic

G. Crystals from Magma 1. Magma → hot, melted rock material beneath Earth’s surface. Magma (cools,) when it reaches Earth's surface.

G. Crystals from Magma As magma cools, the atoms arrange themselves into orderly, repeating patterns. 4. When magma cools quickly, the crystals will be (small). 5. When magma cools slowly, the crystals will be (large).

Crystals from Solution. Crystals can also form from minerals dissolved in water.

Crystals from Solution. When water evaporates, crystals can form. 3. If too much of a substance is dissolved in water, crystals can begin to form in the solution.

Mineral Compositions and Groups How many elements occur naturally in Earth's crust? 90 elements Approximately 98% of the crust is made of only 8 elements.

Mineral Compositions and Groups 3. Silicates  minerals that contain silicon and oxygen and usually one or more other elements. What are the two most abundant elements in Earth’s crust? Silicon and Oxygen

II. Mineral Identification Review Vocabulary: Physical Property  any characteristic of a material that you can observe without changing the identity of the material.

B. Mineral Appearance Can color and appearance alone be used to identify a mineral? Why? No, because there are many minerals that “appear” to be similar.

B. Mineral Appearance 2. An example of two minerals that look alike, but are very different would be gold and pyrite. 3. Color and appearance can be used to identify few minerals. For example, quartz can be: clear, yellow, purple, pink, green, brown, and black. 5. Impurities change the color.

C. Hardness  a measure of how easily a mineral can be scratched.

Hardness  1 What is the softest mineral? Talc What is the hardest mineral? Diamond Even though a diamond is the hardest mineral, if given a hard enough blow, it will shatter.

4. What is the name of the scale that compares the hardness of minerals? Mohs Hardness Scale 5. The hardness of a mineral is expressed as a number. 5. What number represents the softest minerals? 1 6. What number represents the hardest minerals? 10

D. Luster  describes the way a mineral reflects light from its surface. 1. Metallic  shiny like a metal. 2. Nonmetallic  dull, pearly, silky, or glassy appearance.

Specific Gravity → the ratio of a mineral’s weight compared with the weight of an equal volume of water. Specific gravity is expressed as a number. For example, gold has a specific gravity of 19, whereas pyrite has a specific gravity of 5. 3. Which one would feel heavier? gold

D. Streak  is the color of a mineral when it is in powdered form.

Streak 1. A streak plate = unglazed tile, has a hardness of 7. 2. A streak plate can only be used on minerals with a hardness ( less than) 7. 3. For example, gold has a yellow streak and pyrite has a greenish-black streak. 4. Name the mineral that you use to leave a streak on paper: graphite

Cleavage and Fracture  the way a mineral breaks.

Cleavage and Fracture 1. Cleavage  a property of some minerals that causes them to break along smooth, flat surfaces. Example: Mica 2. Fracture  a property of some minerals that causes them to break with uneven, rough or jagged surfaces. Example: Quartz

Other Properties 1. Magnetite = naturally magnetic 2. Calcite = fizzes with hydrochloric acid

Other Properties 3. Halite = tastes salty 4. Sulfur = smells like rotten eggs

III. Uses of Minerals A. Review Vocabulary: Metal  element that typically is a shiny, malleable solid that conducts heat and electricity well.

III. Uses of Minerals Gems  beautiful, rare, highly prized minerals that can be worn in jewelry.

c. Aquamarine h. Tanzanite d. Peridot i. Tourmaline Precious Stones: a. Diamond c. Sapphire b. Ruby d. Emerald Semiprecious Stones: a. Garnet f. Citrine b. Amethyst g. Topaz c. Aquamarine h. Tanzanite d. Peridot i. Tourmaline e. Opal j. Turquoise 35

Other gems, but not minerals a. Pearls = are produced by oysters. b. Amber = fossilized tree sap.

C. Ores  deposits in which a mineral C. Ores  deposits in which a mineral exists in large enough amounts to be mined at a profit.

1. Iron is obtained from hematite. D. What are two examples? 1. Iron is obtained from hematite. 2. Aluminum is obtained from bauxite.

E. During smelting, a substance is melted to separate it from any unwanted materials that may remain.

bicycles, soft-drink cans, foil, airplane and car parts F. What are some uses for aluminum? bicycles, soft-drink cans, foil, airplane and car parts

Vein minerals are metal deposits that occur in the cracks of rocks. Example: Sphalerite is a source for zinc, which is used in batteries.

H. Titanium  a durable, lightweight, metallic element derived from minerals that contain this metal in their crystal structures.

Titanium 1. The two minerals that are the sources of titanium are: ilmenite and rutile 2. List some uses for titanium: Automobile and aircraft parts, eyeglass frames, sports equipment, wheelchairs…