bell ringer: 1.what are the 4 questions you ask yourself when trying to find out if an object is a...
TRANSCRIPT
Bell Ringer: 1.What are the 4 questions you ask yourself when trying to find out if an object is a mineral?
2. What test do you think you would use to identify the type of mineral?
What is a Mineral?What is a Mineral?
Naturally-formed Naturally-formed solidsolid substance substance with a with a crystalcrystal structure structure
Pyromorphite
What do all minerals What do all minerals have in common?have in common?
All:All:1.1. Are formed by Are formed by naturalnatural processes. processes.
2.2. Are Are NOTNOT alive and NEVER were alive alive and NEVER were alive
3.3. Have a Have a definitedefinite volume and shape volume and shape
4.4. Are elements or compounds with a Are elements or compounds with a uniqueunique chemical makeupchemical makeup
5.5. Are made up of particles that are arranged Are made up of particles that are arranged in a pattern that is repeated over and over in a pattern that is repeated over and over (called a (called a CRYSTALCRYSTAL))
Watch “Crystals” by Brainpop…
1.What element are diamonds made from?
2. What do all crystals have in common?
Groups of MineralsGroups of Minerals
Minerals are grouped by the Minerals are grouped 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 (90% (90% of earth’s of earth’s crust)crust)
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 EarthEarth’’s crusts 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)
How do minerals form?How do minerals form?
1) Cooling of 1) Cooling of magmamagma (hot, (hot, liquid liquid rockrock and minerals inside the earth and minerals inside the earth (from the mantle))(from the mantle)) Fast Cooling = No Crystals (mineraloids)Fast Cooling = No Crystals (mineraloids) Medium Cooling = small crystalsMedium Cooling = small crystals Slow Cooling = large crystalsSlow Cooling = large crystals
How do minerals form?How do minerals form?
2) Elements dissolved in 2) Elements dissolved in liquidsliquids (usually water)(usually water)
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 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 light Surface light
reflection reflection metallicmetallic = shiny = 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
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
http://www.childrensmuseum.org/geomysteries/cube/b3.html
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)
Find out more…Find out more… ““ElectronicElectronic”” Hardness Test Hardness Test
http://www.childrensmuseum.org/http://www.childrensmuseum.org/geomysteries/cube/b2.html geomysteries/cube/b2.html
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
Physical Properties of Physical Properties of MineralsMinerals
Density:Density: how much matter is in a how much matter is in a given amount of space. given amount of space. see if the object floats or sinks in see if the object floats or sinks in
water. water. Water’s density is 1:Water’s density is 1:
If it floats = density is less than 1If it floats = density is less than 1 If it sinks= density is more than 1If it sinks= density is more than 1
*THIS IS CALLED SPECIFIC GRAVITY*THIS IS CALLED SPECIFIC GRAVITY
Physical Properties of MineralsPhysical Properties of Minerals (can be used to identify the mineral)(can be used to identify the mineral)
Other PropertiesOther Properties Specific gravity (*excellent clue to Specific gravity (*excellent clue to
mineralmineral’’s identity)s identity) Attraction to Attraction to magnetsmagnets Bending of lightBending of light Reaction with hydrochloric acidReaction with hydrochloric acid Smell & tasteSmell & taste
http://www.childrensmuseum.org/geomysteries/cube/b4.html
Watch Brainpop—“Mineral Identification”
1. If a mineral can scratch your fingernail, the mineral is _______________ than your fingernail.
2. What is luster?
Quick Hardness TestQuick Hardness Test Penny, pencil, fingernailPenny, pencil, fingernail
1. Use your fingernail to try to scratch 1. Use your fingernail to try to scratch the graphite tip of your pencilthe graphite tip of your pencil
2. Now try to scratch the penny with 2. Now try to scratch the penny with your fingernailyour fingernail
3. Rank these 3 materials in order from 3. Rank these 3 materials in order from softest to hardest on an index card. softest to hardest on an index card. Explain why you ranked them this way. Explain why you ranked them this way.