Chapter 2 Mineral

Lesson 1 Minerals Mineral characteristics: A substance Forms in mature Forms in mature Is a solid Is a solid Has a definite chemical makeup Has a definite chemical makeup Has a crystal structure Has a crystal structure

Everywhere! We use minerals all the time Rocks are not minerals But rocks are made up of minerals Minerals are always made up of the same materials in the same proportion Rocks have 2-3 of the characteristics and have different proportions of materials

Solid as a rock? Minerals have definite volume and a rigid shape A liquid and gas cannot be a mineral Liquids can change into solid forms of minerals Example: Water is not a mineral but ice is a mineral

Natural=Nature Minerals are formed by natural processes Form in many ways: Halite (salt) formed from evaporating water Granite formed from cooled molten rock Talc (powder) formed from pressure and heat

Mineral make up Minerals have a chemical make up- specific combination of atoms of elements Element is a substance that contains only one type of atom Atom is the tiniest particle of anything Most minerals are compounds consisting of several elements in specific proportions

Atoms and Crystals Types of atoms that make up a mineral are part of what makes each mineral unique The bond or connection of those atoms is also significant (weak or strong) Crystal is a solid in which the atoms are arranged in an orderly repeating 3 dimensional pattern

Each mineral has its own type of crystal structure A perfect crystal is rare due to gravity Most are imperfect due to limited growth space-other crystals forming next to them Crystal groups are named by their shapes and angles formed through their centers They form all sorts of shapes

Classifying Minerals Group based on their chemical make up Most common-silicates (90%) have oxygen and silicon Next is carbonates that have carbon and oxygen Then oxides that are oxygen joined to a metal

Most Common Crust Elements In the Earth’s crust, we find: Oxygen 47% Silicon 28 % Aluminum 8% Iron 5% Calcium 4% Other 8%

Minerals Minerals Quartz Feldspar Mica Halite Ruby Diamond Granite Ice Copper Graphite Calcite Hematite Fluorite Garnet Pyrite Talc Topaz

Geologist People that study and specialize in rocks and minerals Geologists study the Earth

Lesson 2 How can we identify minerals? Color and Streak Luster Cleavage and Fracture DensityHardness Special properties

Color and Streak 3 factors determine color: mineral ingredient, exposure to water, and crystal defects Some minerals have a different color when they are ground into fine powder The streak is the color of the powder left behind when the mineral is scraped

Luster Luster refers to how much light reflects off the mineral Metallic or nonmetallic Luster may vary from sample to sample Water makes the luster dull

Cleavage and Fracture Cleavage is the tendency of a mineral to break along FLAT surface Fracture is the tendency of mineral to break into IRREGULAR shapes The bond (weak or strong) determines the cleavage or fracture

Density Density refers to the amount of mass in a substance Density is determine by the kinds of atoms that make up the mineral

Hardness Hardness is the resistance of being scratched and is determined by its crystal structure and bond between atoms Mohs Scale measures minerals hardness Talc is the softest and diamond is the hardest A mineral can only be scratched by other minerals that have the same hardness or harder

Special Properties Living organisms form some minerals like calcite from oysters and human bones/teeth Fluorescent minerals glow when exposed to ultraviolet light Some minerals respond to magnets Rare minerals are radioactive and very dangerous

Lesson 3 Minerals are useful in our world: industry, art, and technology Minerals are used for metals for cars and airplanes, quartz and feldspar for glass, fluorite and calcite for toothpaste, silver compounds for photographs, mica and talc for paint, quartz for computer chips, insulators and filters, gold and silver and gems for jewelry, etc….

Minerals form in many ways: Naturally when atoms of one or more elements join together and crystals begin to grow Minerals form when water evaporates Minerals grow from cooled magma Heat and pressure within the Earth cause minerals to form

Mining Minerals Mining is dangerous There are several types of mining: surface mining, strip mining, open pit mining, and deep mining Sometimes mining involves clearing land, blasting holes in land, drill through land, cutting and digging Ore is rocks that contain enough of a mineral to be mined for money (profit)

Surface and Strip Surface mining simply pans for minerals in dirt or in water Strip mining requires all plants, soil and rock to be removed Mining occurs all over the world

Open pit and Deep Open pit mining removes the surface layer of soil and uses explosives to break the rock on the surface Deep mining is only used when the minerals are very deep under ground or under a mountain-lights and oxygen and safety equipment must travel with the miners so low

Geometry of Gems Gems are found in nature but look dull and rough Jeweler uses a grinding wheel to shape and polish gems into jewels Jewelers use geometry to help cut gems into shapes with many small flat surfaces and angles called facets Facets make the gem sparkle TEST TIME!