Table of Contents Properties of Minerals How Minerals Form Using Mineral Resources

What Is a Mineral? - Properties of Minerals A mineral is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition.

5 common mineral characteristics Naturally occurring Inorganic Solid Definite chemical composition (i.e. SiO2) Crystal structure *A mineral must have all 5 of these characteristics! *Otherwise the substance is not considered a mineral!

Properties used to identify a mineral Color (easily observed but not always accurate) Streak (color of a mineral in powder form) Luster (how light is reflected from the surface of a mineral) Density (mass / volume) Hardness (moh’s hardness scale 1-10) Crystal system (atom arrangement gives the mineral it’s shape) Cleavage (mineral that splits along flat surfaces) Fracture (breaks apart in uneven pattern) Special properties (magnetism, fluorescence, reactivity, etc.)

Calculating Density - Properties of Minerals To calculate the density of a mineral, divide the mass of the mineral sample by its volume. Density = Mass/Volume For example, if a sample of olivine has a mass of 237 g and a volume of 72 cm3, then the density is 237 g/72 cm3 = 3.3 g/cm3 Practice Problem A sample of calcite has a mass of 324 g and a volume of 120 cm3. What is its density? 324 g ÷ 120 cm3 = 2.7 g/cm3

Mineral Density - Properties of Minerals Use the line graph of the mass and volume of pyrite samples to answer the questions.

Mineral Density - Properties of Minerals Reading Graphs: What is the mass of Sample B? What is the volume of Sample B? 50 g; 10 cm3

Mineral Density - Properties of Minerals Calculating: What is the density of Sample B? 5 g/cm3

Mineral Density - Properties of Minerals Reading Graphs: What is the mass of Sample C? What is the volume of Sample C? 100 g; 20 cm3

Mineral Density - Properties of Minerals Calculating: What is the density of Sample C? 5 g/cm3

Mineral Density - Properties of Minerals Comparing and Contrasting: Compare the density of Sample B to that of Sample C. The density of samples B and C is the same.

Mineral Density - Properties of Minerals Predicting: A piece of pyrite has a volume of 40 cm3. What is its mass? 8 g

Mineral Density - Properties of Minerals Drawing Conclusions: Does the density of a mineral depend on the size of the mineral sample? Explain. No; density does not depend on size. Larger samples have more mass, but the ratio between mass and volume is constant.

Identifying Minerals - Properties of Minerals The crystals of each mineral grow atom by atom to form that mineral’s particular crystal structure. Geologists classify these structures into six groups based on the number and angle of the crystal faces.

Moh’s Hardness Scale

Properties of Minerals Outlining Properties of Minerals An outline shows the relationship between major ideas and supporting ideas. As you read, make an outline about the properties of minerals. Use the red headings for the main topics and the blue headings for the subtopics. What Is a Mineral? Naturally Occurring Inorganic Solid Crystal Structure Definite Chemical Composition Identifying Minerals Color Streak Luster Density Hardness Crystal Systems Cleavage and Fracture Special Properties

End of Section: Properties of Minerals

Minerals form by the crystallization of magma and lava - How Minerals Form Minerals form by the crystallization of magma and lava Minerals also form from crystallization of materials dissolved in water

Minerals Generally Form in Two Ways: Minerals can form on the surface through evaporation of solutions containing dissolved minerals. Minerals can also form beneath the surface when dissolved elements and compounds leave a hot water solution or when magma cools and hardens.

Terminology Geodes are hollow rocks that contain crystals inside of them Crystallization is the process where atoms are arranged to form a material with a crystal structure *Crystallization occurs in two ways: From magma slow cooling beneath the surface resulting in larger crystals and from lava quickly cooling resulting in smaller crystals (change from liquid to solid state) From solutions (mixture where one substance dissolves in another) *Crystallization occurs when elements and compounds that are dissolved in water leave a solution *This occurs either through evaporation or from hot water solutions representing a vein (a mineral deposit found in surrounding rock)

Asking Questions - How Minerals Form Before you read, preview the red headings. In a graphic organizer like the one below, ask a how or what question for each heading. As you read, write answers to your questions. Questions Answers How do minerals form from magma? They form when magma cools and crystals grow. How do minerals form from solutions? They form when solutions evaporate or cool.

Using Mineral Resources Minerals are the source of gemstones, metals, and a variety of materials used to make many products Gemstones are hard and colorful minerals with a glassy luster Metals typically are not as hard as gemstones, but can be stretched out and molded without breaking Minerals can be found everywhere…even in the foods you eat!

Producing Metals from Minerals Rocks contain many minerals (including metals) and must be removed from the ground and then processed to extract the metal An ore is a metal or other useful mineral that can be sold for a profit A prospector is a person who searches for ores to mine A miner is a person who actually extracts the ores for sale at a later time There are three type of mines: Strip mines Open pit mines Shaft mines

Strip Mines Change the Landscape Forever!

Open Pit Mines

Shaft Mine

Producing Metals From Minerals - Using Mineral Resources Producing Metals From Minerals In the process of smelting, an ore is mixed with other substances and then melted to separate the useful metal from the other elements the ore contains.

Further Processing of Metals Impurities are removed and or additional elements can be added to make a metal stronger. An alloy is a mixture of two or more elements with at least one of the elements being a metal. Example: Steel is produced by adding carbon to iron. *Further processing can result in stronger stainless steel by adding the elements Manganese, Nickel, and Chromium

Using Prior Knowledge - Using Mineral Resources Before you read, look at the section headings and visuals to see what this section is about. Then write what you know about mineral resources in a graphic organizer like the one below. As you read, write what you learn. What You Know The gems used in jewelry are minerals. Metals come from Earth. What You Learned Minerals are also the source of metals and other useful materials, like quartz and gypsum. Most metals come from ores, which are mined and smelted before the metals can be used.

End of Section: Using Mineral Resources

Graphic Organizer Hematite Brick Naturally occurring Human-made Solid or inorganic Crystal structure No crystal structure Inorganic or solid Definite chemical composition Chemical composition varies

End of Section: Graphic Organizer