Minerals Table of Contents Properties of Minerals How

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

Minerals - Properties of Minerals What Is a Mineral? • Mineral – naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition. • A substance must have 5 characteristics in order to be considered a mineral: 1. Naturally occurring – substance cannot be man made 2. Inorganic - the substance cannot form from materials that were once part of a living thing

Minerals What Is a Mineral? 3. Solid – substance must be a solid with a definite volume and shape 4. Crystal - a solid in which the atoms are arranged in a pattern that repeats again and again 5. Definite Chemical Composition – the substance always contains certain elements in definite proportions

Minerals

Minerals Identifying Minerals • Geologists have identified about 3, 800 minerals. Each mineral has characteristic properties that can be used to identify it. • Color – can be used to identify only those few minerals that always have their own characteristic color – Ex: Malachite is always green; Azurite is always blue

Minerals Identifying Minerals • Streak – the color of a mineral’s powder. – Observe a streak by rubbing a mineral against a piece of unglazed porcelain tile – Streak color and mineral color are often different.

Minerals Identifying Minerals • Luster – the way a mineral reflects light from its surface. – There are many different terms used to describe various lusters. They include: metallic, glassy, earthy, waxy, brilliant, and pearly

Minerals Identifying Minerals • Density – mass in a given space or volume – No matter what the size of a mineral sample, the density of that mineral always remains the same.

Minerals - Properties of Minerals Calculating Density • 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 cm 3, then the density is 237 g/72 cm 3 = 3. 3 g/cm 3

Minerals - Properties of Minerals Calculating Density • Practice Problem • A sample of calcite has a mass of 324 g and a volume of 120 cm 3. What is its density? • 324 g ÷ 120 cm 3 = 2. 7 g/cm 3

Minerals Identifying Minerals • Hardness – refers to the mineral’s ability to resist scratching. – Mohs hardness scale – ranks ten minerals from softest to hardest

Minerals Talc 1 Gypsum 2 Calcite 3 Fluorite 4 Apatite 5 Feldspar 6 Quartz 7 Topaz 8 Corundum 9 Diamond 10 Easily scratched by fingernail Can be scratched by copper penny Easily scratched with steel file/glass Scratches glass with difficulty Easily scratches both glass and steel Scratches quartz No simple tests Scratches everything

Minerals Identifying Minerals • Crystal systems - crystals of each mineral grow atom by atom to form that mineral’s crystal structure. – Classified into six groups based on the number and angle of the crystal faces • Cleavage – mineral’s ability to split easily along flat surfaces. – Fracture – the way a mineral looks when it breaks apart in an irregular way.

Minerals Identifying Minerals • Special properties - some minerals can be identified by special physical properties – Ex: magnetism (Magnetite), fluorescence (Sheelite), radioactivity, reaction to acids, optical and electrical properties

Minerals - Properties of Minerals Identifying Minerals

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

Minerals - Properties of Minerals Mineral Density • Reading Graphs: • What is the mass of Sample B? What is the volume of Sample B? 50 g; 10 cm 3

Minerals - Properties of Minerals Mineral Density • Calculating: • What is the density of Sample B? 5 g/cm 3

Minerals - Properties of Minerals Mineral Density • Reading Graphs: • What is the mass of Sample C? What is the volume of Sample C? 100 g; 20 cm 3

Minerals - Properties of Minerals Mineral Density • Calculating: • What is the density of Sample C? 5 g/cm 3

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

Minerals - Properties of Minerals Mineral Density • Predicting: • A piece of pyrite has a volume of 40 cm 3. What is its mass? 8 g

Minerals - Properties of Minerals Mineral Density • Drawing Conclusions: • Does the density of a mineral depend on the size of the mineral sample? Explain. No; Larger samples have more mass, but the ratio between mass and volume is constant.

Minerals - Properties of Minerals Crystal Systems Activity • Click the Active Art button to open a browser window and access Active Art about crystal systems.

Minerals - Properties of Minerals Data Sharing Lab • Click the PHSchool. com button for an activity about sharing data for the Skills Lab Finding the Density of Minerals.

Minerals - How Minerals Form Where Minerals Form • Minerals form on surfaces through evaporation of solutions containing dissolved minerals. • Minerals form beneath surfaces when dissolved elements and compounds leave a hot water solution or when magma cools and hardens.

Minerals - How Minerals Form Where Minerals Form • Geode – a hollow rock inside which mineral crystals have grown. • Crystallization – process by which atoms are arranged to form a material with a crystal structure.

Minerals - How Minerals Form Minerals From Solutions • Solution – a mixture in which one substance is dissolved in another. – When elements and compounds that are dissolved in water leave a solution, crystallization occurs. • Some minerals form when solutions evaporate – Ex: salt crystals (Halite), Gypsum, Calcite

Minerals - How Minerals Form Minerals From Solutions • Other mineral crystals form from hot water solutions that begin to cool. – Many times the hot water is a result of geothermal (underground) heat – Ex: Silver Pure metals that crystallize from hot water solutions underground often form veins Vein – a narrow channel or slab of a mineral that is different from the surrounding rock.

Minerals - How Minerals Form More on Mineral Formation • Click the PHSchool. com button for an activity about mineral formation.

Minerals - Using Mineral Resources The Uses of Minerals • Minerals are the source of gemstones, metals, and a variety of materials used to make many products. – Gemstone – a hard, colorful mineral that has a brilliant or glassy luster. • Mainly used for decoration and jewelry, but can be used for grinding and polishing.

Minerals - Using Mineral Resources Rubies • Click the Video button to watch a movie about rubies.

Minerals - Using Mineral Resources The Uses of Minerals – Metals – not as hard as gemstones but can be molded without breaking • Used in building supplies, tools, framings, etc. • People use materials from these minerals in foods, medicines, fertilizers, and building materials.

Minerals - Using Mineral Resources Producing Metals From Minerals • To produce metal from a mineral: – A rock containing the mineral must be located through prospecting and mined (removed from the ground) – Then the rock must be processed to extract the metal.

Minerals - Using Mineral Resources Producing Metals From Minerals • Ore – rock that contains a metal or economically useful mineral. • Prospector – anyone who searches, or prospects, for an ore deposit. • Once found, miners outline a plan for digging up the ore. There are three types of mines: – strip mines, open pit mines, and shaft mines

Minerals - Using Mineral Resources Producing Metals From Minerals • Strip mine – large pieces of equipment are used to scrape away soil to expose ore • Open pit – large pieces of equipment are used to dig a tremendous pit and remove ore deposits • Shaft mines - have a network of tunnels that extend deep into the ground, following the veins of ore.

Minerals - Using Mineral Resources Links on Mining Minerals • Click the Sci. Links button for links on mining minerals.

Minerals - Using Mineral Resources Producing Metals From Minerals • Smelting – an ore is mixed with other substances and then melted to separate the useful metal from the other elements the ore contains.

Minerals - Using Mineral Resources Producing Aluminum • Click the Video button to watch a movie about producing aluminum.

Minerals - Using Mineral Resources Producing Metals From Minerals • Once smelted, the impurities will be removed. • At this point some metals can be melted together to form alloys • Alloy – a solid mixture of two or more elements, at least one of which is a metal. – Ex: Steel

Minerals Graphic Organizer Hematite Brick Naturally occurring Crystal structure Definite chemical composition Man-made Solid Inorganic No crystal structure Chemical composition varies