2What is a Mineral?Naturally-formed solid substance with a crystal structurePyromorphite
3What do all minerals have in common? Are formed by natural processes.Are NOT alive and NEVER were aliveHave a definite volume and shapeAre elements or compounds with a unique chemical makeupAre made up of particles that are arranged in a pattern that is repeated over and over (called a CRYSTAL)
4What do all minerals have in common? They must occur naturally within the earth.Cement, bricks, steel, and glass are not minerals because they are man made.
5What do all minerals have in common? Minerals must be inorganic. This means that they cannot arise from materials that were once part of a living thing.Coal is not a mineral because it comes from the remains of plants and animals
6What do all minerals have in common? Minerals have a definite volume and shape.The particles that make up the sample do not move apart.
7What do all minerals have in common? Minerals have definite chemical compositions.A mineral always contains certain elements in definite proportions.Most minerals are compounds.Compounds are two or more elements combined.Some minerals are just elements Copper, Gold, and Silver.
8What do all minerals have in common? Minerals have crystal structures. These are particles in minerals that line up in a pattern that repeats over and over again.Sometimes a crystal structure is obvious and sometimes its only visible under a microscope.
9Watch “Crystals” by Brainpop… .What element are diamonds made from?. What do all crystals have in common?
10Groups of MineralsMinerals are grouped by the elements they are made of.Beryl (Emerald)CalciteAmethyst
11Contain oxygen & silica The most abundant group of minerals Mineral GroupCharacteristicsExamplesSilicatesContain oxygen & silicaThe most abundant group of mineralsQuartz, micaMICAQuartz
12Make up only 5% of the Earth’s crust Mineral GroupCharacteristicsExamplesNon-SilicatesMake up only 5% of the Earth’s crustInclude some of the most important mineralsiron, copper, gold, silver, diamonds, rubiesSilverCopperDiamondGoldIronRuby
13Carbon & oxygen and a positive ion, such as calcium Calcite (CaCO3) Mineral GroupCharacteristicsExamplesCarbonatesCarbon & oxygen and a positive ion, such as calciumCalcite (CaCO3)Calcite with Duftite inclusions
14Mineral GroupCharacteristicsExamplesOxidesMetallic ion and oxygenHematite (Fe2)O3
15Mineral GroupCharacteristicsExamplesSulfidesSulfur and a metallic ionGalena (PbS)
16Metallic ion, Sulfur & oxygen Barite (BaSO4) Mineral GroupCharacteristicsExamplesSulfatesMetallic ion, Sulfur & oxygenBarite (BaSO4)Barite BaSo4Barite on Calcite BaSo4 / CaCO3
18How do minerals form?1) Cooling of magma (hot, liquid rock and minerals inside the earth (from the mantle))Fast Cooling = No Crystals (mineraloids)Medium Cooling = small crystalsSlow Cooling = large crystals
19How do minerals form?2) Elements dissolved in liquids (usually water)
20Physical Properties of Minerals Mineral appearanceHardnessLusterSpecific gravityStreakCleavage and fracture
21Physical Properties of Minerals (can be used to identify the mineral) ColorCan be misleadingCan vary with the type of impurities
22Physical Properties of Minerals (can be used to identify the mineral) HardnessHow easily a mineral scratches materialsMohs Hardness ScaleScale from 1 (softest) to 10 (hardest)Test by seeing if the mineral can scratch different objects (like human fingernail, copper, penny, glass, steel file)
23Properties of Minerals Mohs Hardness ScaleMineralTalcGypsumCalciteFluoriteApatiteFeldsparQuartzTopazCorundumDiamondRatingTesting Method1 Softest known mineral. It flakes easily when scratched by a fingernail.2 A fingernail can easily scratch it.3 A fingernail cannot scratch it, but a copper penny can.4 A steel knife can easily scratch it.5 A steel knife can scratch it.6 Cannot be scratched by a steel knife, but it can scratch window glass.7 Can scratch steel and hard glass easily.8 Can scratch quartz.9 Can scratch topaz.10 Hardest known mineral. Diamond can scratch all other substances.
25Physical Properties of Minerals (can be used to identify the mineral) LusterSurface reflectionmetallic = shiny like metalnon-metallic = dull, non-shiny surfacePyrite has a metallic lusterCalcite has a non-metallic luster
26Specific Gravity or Density The specific gravity of a mineral is the ratio of its mass compared with the mass of an equal volume of water.Gold has specific gravity of 19It means gold is 19 times heavier than water.19 times heavier
28Physical Properties of Minerals (can be used to identify the mineral) StreakThe color of the powdered form of the mineralThe color of the streak can be different than the mineralMinerals must be softer than the streak plate
30Physical Properties of Minerals (can be used to identify the mineral) Cleavage & FractureThe way the mineral breaksCleavage—minerals break along smooth, flat surfaces and every fragment has the same general shapeFracture—minerals that break at random with rough or jagged edges
31Cleavage Cleavage is the way that mineral breaks. Minerals that break along smooth, flat surfaces have cleavage.Mica has cleavage
32and Fracture!...Mineral that breaks uneven, rough, or jagged surfaces have fracture.Quartz has fracturequartz
33Identify the minerals below for cleavage and fracture
34Physical Properties of Minerals (can be used to identify the mineral) Other PropertiesSpecific gravity (*excellent clue to mineral’s identity)Attraction to magnetsBending of lightReaction with hydrochloric acidSmell & taste
35An illustration appearance:luster,color and streak