2.1 Minerals Are All Around Us

1. 2.1 Minerals Are All Around Us Minerals are basic building blocks of Earth

2. Minerals are all around us. • Minerals are used all the time. • Copper in the wires that carry electricity to a device • Table salt, or halite (HAYL-YT), is a mineral • Minerals and rocks are not the same. • Minerals • Formed in nature • Solid • Definite chemical makeup • Crystal structure • Always made up of the same materials in the same proportions • Rocks • Formed in nature • Solid • Usually contains two or more types of minerals • Amounts of minerals may vary between the same types of rock

4. Minerals have four characteristics. Is formed in nature Is a solid Has a definite chemical makeup Has a crystal structure

5. Formed in Nature • Minerals are formed by natural processes • Every mineral can form without involvement by living organisms • A few can be produced as part of an organisms shells or bones. • Form in many ways • Halite (table salt) is formed when ocean water evaporates • Granite develops when molten rock cools. • Talc (found in baby powder) is formed from the high pressure and temperature deep in Earth.

6. Solid • A mineral has a definite volume and a rigid shape • Liquids and gases are not minerals unless they are in solid form • Examples • Liquid water is not a mineral, but ice is. • Copper is a mineral when in solid form, but melted copper is a liquid, so it is not considered a mineral.

7. Definite Chemical Makeup • Each mineral consists of a specific combination of atoms of certain elements. • Elements are substances that contain only one type of atom • Atoms are the smallest particle an element can be divided into • Everything is made up of atoms. • Some minerals (gold, copper) consist of one element of the same type • Most minerals are compounds, substances consisting of several elements in specific proportions (NaCl) • The types of atoms in a mineral help to make it unique • Atom bonds also help make it unique

10. Crystal Structure • Arrangements of atoms are characteristic of minerals • Crystals are solids in which the atoms are arranged in an orderly, repeating, three-dimensional pattern • Each mineral has its own type of crystal structure • Two minerals can have the same chemical composition but different crystal structures. • Diamond and graphite • Consist only of carbon • Arrangement of the carbon atoms result in different crystal structures and properties. • Diamonds are extremely hard and have a brilliant sparkle. • Graphite is soft, gray, and dull. • Perfect crystals rarely form in nature. • Needs to form in open space • Amount of growing space influences shape and size of crystals.

14. Minerals are grouped according tocomposition. • Minerals are classified based on their chemical makeups • Out of thousands of minerals, only 30 are common in Earth’s crust • Called rock-forming minerals and make up most rocks in the crust. • Most common are silicates • Contain oxygen and silicon (most common elements in crust) joined together • Make up about 90 percent of the rocks in Earth’s crust • Most common rock-forming minerals are Quartz, Feldspar, Mica • Carbonates • Contain carbon and oxygen joined together • Second most common group of rock-forming minerals • Many other important mineral groups. • oxides contains the minerals from which most metals (tin, copper), are refined. • Consists of an element, usually a metal, joined to oxygen (hematite)

15. Minerals are grouped according to composition. Silicates are the most common rock-forming mineral group. Carbonates are the second most common mineral group. The oxides group contains the minerals from which most metals are refined

16. Minerals are grouped according to composition. • Give three examples of silicates. • Quartz • Feldspar • Mica • What are rock-forming minerals? List some examples. • Rock-forming minerals are a group of about 30 minerals that make up most of the rocks in Earth’s crust. Some examples are quartz, feldspar, mica, and calcite.