Unit Introduction

Think pair share 1) What is a mineral? 2) Give 3 examples of minerals and what each is used for 3) Explain what a crystal is 4) what is the difference between rocks and minerals

VA SOL ES 5 The student will investigate and understand how to identify major rock-forming and ore minerals based on physical and chemical properties. Key concepts include b. use of minerals.

Objective 1. Identify the major elements of the Earth’s crust. 2. Identify common minerals and ores and their uses. Include: quartz, calcite, talc, gypsum, fluorite, feldspar, biotite, muscovite, hematite, galena, halite, pyrite, magnetite, sulfur, and graphite. 3. Identify Virginia’s major rock and mineral resources and their uses.

Minerals What is a Mineral?

Enduring Understanding Minerals are the building blocks of rocks.

Minerals Earth’s crust is composed of about 3,000 different minerals. They play very important roles in civilization. Throughout history wars have been waged and empires have risen and fallen over the conquest of a select few minerals such as gold and silver considered to be precious.

Mineral Characteristics Mineral is a naturally occurring, inorganic solid with a specific chemical composition and a definite crystalline structure Naturally Occurring means they are formed by natural processes

Mineral Characteristics Synthetic diamonds and other materials developed in labs are not minerals

Mineral Characteristics Inorganic means that they are not and never were alive Salt is a mineral, sugar is not

Mineral Characteristics Solid - means it has a definite shape and volume No liquids or gases can be minerals!!!

Mineral Characteristics Specific Chemical Composition - means that since most minerals are compounds, the elements and their proportions are unique to that mineral The chemical composition for Quartz is SiO2, with a chemical breakdown of approximately 46.7% silicon and 53.3% oxygen.  Quartz is easily transformed from low to high quartz at 573 degrees Celsius with only minor atomic adjustments and without breaking any of the Si-O bonds.

Mineral Characteristics Some minerals such as silver are found as a single element

Mineral Characteristics Definite Crystalline Structure - means the atoms are arranged in regular geometric patterns that are repeated over and over. There are six major crystal systems:

Cubic

Tetragonal

Hexagonal Beryl

Orthorhombric Olivine

Monoclinic Amphibole

Triclinic Turquoise

Mineral Formation Since minerals must form from natural processes there are two primary ways that they form here on Earth

Mineral Formation Minerals can form from the cooling of magma which is the molten material found beneath Earth’s surface. As magma rises closer to the surface, the molten compounds no longer move freely and they begin to interact chemically to form minerals.

Mineral Formation Small crystals means the magma cooled rapidly

Mineral Formation Large crystals means the magma cooled more slowly

Mineral Formation Minerals also form from solution such as when a liquid evaporates from the solution and the elements remain behind “Evaporites”

Mineral Formation Minerals will precipitate (drop out) of a solution that becomes supersaturated meaning it can hold no more dissolved solids

Mineral Groups Of the 3,000 minerals found in the crust only about 30 of these are common. Ten of these make up about 90% of the Earth’s crust

Mineral Groups Silicates are the most abundant group (96%) containing the two most abundant elements in the crust Silicon (Si) and Oxygen (O)

Mineral Groups Quartz and Feldspar are the most abundant minerals

Mineral Groups Carbonates are minerals composed of one or more metallic elements with the carbonate compound CO3

Mineral Groups Calcite and dolomite are common examples

Mineral Groups Carbonates are the primary minerals in rocks such as limestone, coquina, and marble

Mineral Groups Oxides are compounds of oxygen (O) and a metal. Hematite (Fe2O3) and Magnetite (Fe3O4) are common examples