GEOS - 3. Minerals
Card Set Information
GEOS - 3. Minerals
For Exam 1
What are the four most common elements on EartH?
What are the 3 most common elements in the crust?
What is a rock?
Attached assemblage of minerals
What is the term for the study of rocks?
Natural, inorganic solid which characteristic chemical compositions and internal structure; crystalline substances
What is concrete not a rock?
It is a manmade material
What is a crystal?
Repeated regular arrangement of specific elements in a solid; thus symmetry is built in
What are the methods used to identify minerals?
Hand sample, thin section, geochemistry, geophysics
How does the thin section method of identifying minerals work?
Slice the rock into a thin section. Put it under a microscope and shine a light through it - this can be used to identify minerals by optical properties
How does the geochemistry method of identifying minerals work?
X-ray diffraction, looking at the chemistry of the rock scale, mineral scale, and atomic scale
How does the geophysics method of identifying minerals work?
Look at sounds speeds through rocks
What are silicates made predominantly out of?
Silicon & oxygen
How are silicates constructed?
In an octahedron or tetrahedron form; in between negatively charged silicate groups are positively charged cations
What is the difference between silicate octohedron and silicate tetrahedron?
Octahedra are sharing corners; most of the rocks we will touch are tetrahedrons, which can stand alone; tetrahedron are bonded together in sheets or in 3D frameworks
Silicates make up greater than ___ percent of the planet.
What are silicates used for?
Many industrial rocks and minerals, many ores, clay, and gems
Makes up most of the lower mantle
Most common mineral in earth
Is exceedingly rare on the surface of the planet
What is the trend between distance from mantle and the presence of iron and magnesium?
As you get more and more away from the mantle, you get less and less iron and magnesium
An iron magnesium silicate
65+% of the upper part of the mantle
Low pressure mineral
Also seen in the crust but is it not in the top five.
Iron magnesium silicate
Can contain calcium and aluminum
Common in upper mantle and ocean crust
Forms chains, a little more of a complex structure than tetrahedron
Common in upper mantle
Has various elements
: Fe, Mg, Al, Ca, Cr
Has a complex 3D framework
Makes up ~10% of upper mantle
A minor component of the crust
In the crust
Has water in the mineral
Iron magnesium silicate; include OH-
May include aluminum, calcium, Na
Amphiboles include hornblende
Double chain structure
Have aluminum and OH-
Can have Fe, MG, K, Ca, Na
A huge family of minerals
Also hydrated like micas
Must have Aluminum and OH-
May have K, Na, Ca, Mg
Comes from breaking down minerals w/ water (weathering)
Most common mineral group at Earth's surface
No water built into them
Most common mineral in both the ocean crust and continental crust
Do not exist in the mantle
Have a more 3D framework
Nothing but silicate
Fairly common in the continents but not so much in the ocean
Common on earth's surface bc it doesn't break down under earth and water
Sand is usually made of this mineral
Two oxygen ions for every silicon ion in the structure
What are carbonates, sulphates, and phosphates used for?
Chemicals, fertilizers, industrial rocks (plaster)
Common in upper crust
found in shells and limestone
Water soluble; found in caves
Plaster of Paris drywall
Biggest crystals we've ever seen are gypsum in New Mexico
Where can apatite be found?
Bones and fertilizer
What is the most common cation in oxides, hydroxides, and sulphides?
What is galena used for?
What are oxides, hydroxides, and sulphides used for?
More common sulfide
Aka fool's gold
Not a good iron mineral; no economic value
Looks cubic, unlike real gold
What are halides?
What are halides used for?
Chemicals (salts), fertilizer (potassium)
What is halite more commonly known as?
We get most of it not by evaporating salt water, but from mining (mining is cheaper)
What is asbestos used for?
A lot of people who work with these end up with this in their lungs --> dying
Discuss toxicity, hazards, regulation of asbestos
Removal costs billions of dollars
Chrysotile = 95% asbestos use, the least toxic
Risk primarily in high concentrations over a long time
It is only a concern for those who work with asbestos - mining, construction, renovations, etc. (occupational exposure)