what is a mineral? naturally occurring naturally occurring solid substance solid substance orderly...
TRANSCRIPT
What is a mineral?What is a mineral?
Naturally occurringNaturally occurring Solid substanceSolid substance Orderly crystalline structureOrderly crystalline structure Definite chemical compositionDefinite chemical composition Generally INORGANICGenerally INORGANIC
Some animals secrete inorganic compounds Some animals secrete inorganic compounds (Calcium carbonate found in shells and coral (Calcium carbonate found in shells and coral reefs)reefs)
Characteristics of MineralsCharacteristics of Minerals
More than 4000 minerals More than 4000 minerals identified, but only 20 are identified, but only 20 are commonly foundcommonly found
Those 20 are known as Those 20 are known as rock-forming minerals, form rock-forming minerals, form the rocks of Earth’s crustthe rocks of Earth’s crust
Of the 20 most common, Of the 20 most common, half of them make up 90% half of them make up 90% of the mass of Earth’s crustof the mass of Earth’s crust
Groups of MineralsGroups of Minerals
Minerals are classified by the Minerals are classified by the elements they are made of.elements they are made of.
Amethyst
Beryl (Emerald) Calcite
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
SilicatesSilicates
Contain Contain oxygenoxygen & & silicasilicaThe most The most abundantabundant group of group of mineralsminerals (95%)(95%)
Quartz, micaQuartz, mica
MICA Quartz
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
Non-SilicatesNon-Silicates
Make up only Make up only 5%5% of the of the Earth’s crustEarth’s crustInclude some Include some of the most of the most important important mineralsminerals
iron, copper, iron, copper, gold, silver, gold, silver, diamonds, diamonds, rubiesrubies
Silver
GoldRuby Iron
Copper
Diamond
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
CarbonatesCarbonates Carbon & Carbon & oxygen and oxygen and a positive a positive ion, such as ion, such as calciumcalcium
Calcite Calcite (CaCO(CaCO33))
Calcite with Duftite inclusions
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
OxidesOxides Metallic ion Metallic ion and oxygenand oxygen
Hematite Hematite (Fe(Fe22)O)O33
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
SulfidesSulfides Sulfur and a Sulfur and a metallic ionmetallic ion
Galena (PbS)Galena (PbS)
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
SulfatesSulfates Metallic ion, Metallic ion, Sulfur & Sulfur & oxygenoxygen
Barite Barite (BaSO(BaSO44))
Barite on Calcite BaSo4 / CaCO3
BariteBaSo4
Mineral GroupMineral Group CharacteristicsCharacteristics ExamplesExamples
Native Native ElementsElements
Single Single elementselements
Gold (Au), Gold (Au), Diamond (C), Diamond (C), Silver (Ag)Silver (Ag)
Chemical Formulas to KnowChemical Formulas to Know Gold - AuGold - Au Silver - AgSilver - Ag Copper - CuCopper - Cu Sulfur - SSulfur - S Diamond - CDiamond - C Graphite - C Platinum Graphite - C Platinum
- Pt- Pt Quartz - SiOQuartz - SiO22
Olivine - (Mg, Fe)Olivine - (Mg, Fe)22SiOSiO44
Hematite - FeHematite - Fe22OO33
Magnetite - FeMagnetite - Fe33OO44
Corundum - AlCorundum - Al22OO33
Galena - PbSGalena - PbS Sphalerite - ZnSSphalerite - ZnS Pyrite - FeSPyrite - FeS22
Halite - NaClHalite - NaCl Fluorite - CaFFluorite - CaF22
Calcite - CaCOCalcite - CaCO33
Crystal StructureCrystal Structure All minerals have a All minerals have a
crystalline structurecrystalline structure A A crystal crystal is a solid is a solid
whose atoms, ions, or whose atoms, ions, or molecules are molecules are arranged in a regular, arranged in a regular, repeating patternrepeating pattern Each type of mineral Each type of mineral
crystal is defined by a crystal is defined by a specific geometric specific geometric arrangement of atomsarrangement of atoms
Physical Properties of Physical Properties of MineralsMinerals
ColorColor LusterLuster StreakStreak Hardness Hardness CleavageCleavage FractureFracture
Crystal SystemCrystal System DensityDensity Special Special
PropertiesProperties
Physical Properties of MineralsPhysical Properties of Minerals (can be used to identify the mineral)(can be used to identify the mineral)
ColorColor Can be Can be misleadingmisleading
For example, Quartz comes in a variety For example, Quartz comes in a variety of colorsof colors
Can vary with the type of impuritiesCan vary with the type of impurities
Physical Properties of MineralsPhysical Properties of Minerals (can be used to identify the mineral)(can be used to identify the mineral)
LusterLuster Surface Surface reflectionreflection metallic = shiny metallic = shiny
like metallike metal non-metallic = non-metallic =
dull, non-shiny dull, non-shiny surfacesurface
Pyrite has a metallic luster
Calcite has a non-metallic luster
Non-metallic LusterNon-metallic Luster
Non-Metallic lusters include:Non-Metallic lusters include: Vitreous (glassy) Vitreous (glassy) Pearly (pearl-like)Pearly (pearl-like) Silky (fiber-like)Silky (fiber-like) Earthy (dull)Earthy (dull)
Non-metallic luster Non-metallic luster Continued.Continued.
Non-metallic lusters include:Non-metallic lusters include: Waxy (greasy appearance)Waxy (greasy appearance) Adamantine (diamond-like)Adamantine (diamond-like) Resinous (plastic-looking)Resinous (plastic-looking)
Physical Properties of MineralsPhysical Properties of Minerals (can be used to identify the mineral)(can be used to identify the mineral)
StreakStreak The The colorcolor of the powdered of the powdered
form of the mineralform of the mineral The color of the streak can The color of the streak can
be different than the mineralbe different than the mineral Minerals must be Minerals must be softersofter than than
the streak platethe streak plate
Streak…can help identify Streak…can help identify quartzquartz
Can oil and natural gas be Can oil and natural gas be classified as minerals? Why classified as minerals? Why
or why not?or why not? Answer: Oil and natural gas cannot Answer: Oil and natural gas cannot
be classified as minerals, because be classified as minerals, because they are not solids, do not form they are not solids, do not form crystals, and do not have a definite crystals, and do not have a definite chemical make-upchemical make-up
Physical Properties of MineralsPhysical Properties of Minerals (can be used to identify the mineral)(can be used to identify the mineral)
Cleavage & FractureCleavage & Fracture The way the mineral The way the mineral breaksbreaks CleavageCleavage—minerals break —minerals break
along along smoothsmooth, flat surfaces , flat surfaces and every fragment has the and every fragment has the same general shapesame general shape
FractureFracture—minerals that —minerals that break at break at randomrandom with rough with rough or jagged edgesor jagged edges
Types of CleavageTypes of Cleavage Basal - 1 planeBasal - 1 plane Prismatic - 2 Prismatic - 2
planesplanes Cubic - 3 planes Cubic - 3 planes
@ 90@ 90 Rhombohedral - 3 Rhombohedral - 3
planes not @ 90planes not @ 90 Octahedral - 4 Octahedral - 4
planesplanes Dodecahedral - 6 Dodecahedral - 6
planesplanes
Types of FractureTypes of Fracture Conchoidal – curvedConchoidal – curved Irregular – unevenIrregular – uneven Fibrous – splinteryFibrous – splintery Hackly – jagged-Hackly – jagged-
edgededged
Physical Properties of MineralsPhysical Properties of Minerals (can be used to identify the mineral)(can be used to identify the mineral)
HardnessHardness How easily a mineral How easily a mineral scratchesscratches
materialsmaterials Mohs Hardness ScaleMohs Hardness Scale
Scale from 1 (Scale from 1 (softestsoftest) to 10 () to 10 (hardesthardest)) Test by seeing if the mineral can scratch Test by seeing if the mineral can scratch
different objects (like human fingernail, different objects (like human fingernail, copper, penny, glass, steel file)copper, penny, glass, steel file)
2.5, 3.5, 5.5, 6.52.5, 3.5, 5.5, 6.5
Crystal SystemCrystal System Crystal form is the visible expression of a Crystal form is the visible expression of a
mineral’s internal arrangement of atomsmineral’s internal arrangement of atoms Every mineral has a crystal formEvery mineral has a crystal form
DensityDensity
Special PropertiesSpecial Properties Magnetism Magnetism Attraction to Attraction to magnets magnets Smell & tasteSmell & taste Fluorescence Fluorescence glows under UV light glows under UV light Phosphorescence Phosphorescence glows after UV glows after UV
light is off (stores light energy light is off (stores light energy longer)longer)
Special PropertiesSpecial Properties Effervescence Effervescence fizzing (HCl on fizzing (HCl on
calcite)calcite) Chatoyancy Chatoyancy silky band when light silky band when light
shined on mineralshined on mineral Asterism Asterism six-sided star appears six-sided star appears
when lightwhen light
Special PropertiesSpecial Properties Double refraction – Double refraction –
light is bent, causing light is bent, causing image to be doubledimage to be doubled Ex. CalciteEx. Calcite
Radioactivity Radioactivity Geiger counterGeiger counter
Describe what would Describe what would happen if you rubbed a happen if you rubbed a
mineral with a Mohs mineral with a Mohs hardness value of 7 against hardness value of 7 against a mineral with a value of 5.a mineral with a value of 5.
The one with a hardness of 5 would The one with a hardness of 5 would be scratched, because the mineral be scratched, because the mineral with a hardness of 7 is harder.with a hardness of 7 is harder.