What is a Mineral Must be a solid Must occur in nature Must have a definable chemical composition NaCl Must have a crystalline structure Must be inorganic Video httpwwwyoutubecomwatchvrTXSwnkieZc ID: 918032
Download Presentation The PPT/PDF document "Properties of Minerals Geologists use ch..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Properties of Minerals
Geologists use characteristics to tell one mineral from another
Slide2What is a Mineral?
Must be a solid.
Must occur in nature.
Must have a definable chemical composition (
NaCl
).
Must have a crystalline structure.
Must be inorganic.
Video:
http://www.youtube.com/watch?v=rTXSwnkieZc
Slide3Mineral Properties we will mainly study:
Luste
r
Hardness
Cleavage
Streak
Slide4Special Properties
Fluorescence
Optical Properties: double refraction
Taste
Conductivity
Reaction to AcidMagnetismDensity
Video:
http://www.youtube.com/watch?v=cjA2-MrWAVUSong: http://www.youtube.com/watch?v=Sv_ApO7xiv8
Slide5Mineral Special Properties (magnetism, acid, specific gravity, fluorescence, double refraction)
8:16:
https://www.youtube.com/watch?v=g1AeCxrsC2Q
Slide6Luster
Refers to the way light reflects from the surface of the mineral.
There are two types of luster,
Metallic: looks like polished metal.
Nonmetallic: does not look like polished metal.
Nonmetallic can be shiny or dull.
Slide7Pyrite has metallic luster
Slide8Quartz has nonmetallic luster
Slide9Hardness
Is measured by how easy it is to scratch.
Geologists
use
Mohs
Hardness Scale
Slide10Gypsum is soft, it can be scratched by a fingernail.
Slide11Calcite is soft, but a little harder because it cannot be scratched by a fingernail, but it can be scratched by a penny.
Slide12Fluorite is harder. It can be scratched by a nail, but not a penny or fingernail.
Slide13Diamonds are the hardest mineral, so it scratches every mineral.
Slide14Cleavage
Not all minerals have cleavage.
Some minerals split easily along a flat surface.
The number of lines that are created when a mineral is split will be the number of cleavage lines.
Slide15Mica has cleavage in one direction.
It breaks along one line.
Slide16Feldspar has two lines of cleavage. It breaks along two lines.
Slide17Streak
Red chalk on a chalk board makes red marks. White chalk makes white marks.
Not all minerals work this way. When some minerals are scratched along a ceramic streak plate, it creates a different color.
Slide18Gold
When gold is run across a streak plate it makes a yellowish-gold color.
That makes sense.
Slide19Pyrite or “Fool’s Gold”
When pyrite is run across a streak plate, it has a black or dark green streak.
Pyrite is not worth much money, while gold is worth a lot. They look alike, so miners call it fool’s gold.
Slide20Hematite
Hematite’s color is grey, but its streak is red.
Hema means blood.
The mineral was named hematite because it looked like it was bleeding when it was taken across a streak plate.
Slide21One mineral property we will
not
use…
COLOR
Slide22A mineral can be many different colors. Below is Mica.
Slide23Many minerals can be the same color. Below are gold colored minerals. Which one is gold?
Slide24The answer…
None of them were real gold.
Slide25Just like with people…
Outside color does not tell you much about the important characteristics.
Slide26Videos: Mineral Identification
http://www.youtube.com/watch?v=VnM8ebB06MU
Hardness Scale
https://
www.youtube.com/watch?v=82xu9OxE4q8