Rocks and Minerals B/C

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OrigamiPlanet
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Re: Rocks and Minerals B/C

Postby OrigamiPlanet » October 3rd, 2017, 12:40 pm

1. Phenocryst
2. Vitreous
3. Vesicle
4. Cleavage
5. Twinning
6. Peat
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dxu46
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Re: Rocks and Minerals B/C

Postby dxu46 » October 3rd, 2017, 2:24 pm

1. Phenocryst
2. Vitreous
3. Vesicle
4. Cleavage
5. Twinning
6. Peat
1. a crystal on a rock that is especially conspicuous
2. glassy or looking like glass
3. air pockets
4. a sharp division
5. two or more crystals forming within each other.
6. the lowest grade of coal, with lowest carbon concentration

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whythelongface
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Re: Rocks and Minerals B/C

Postby whythelongface » October 3rd, 2017, 9:12 pm

1. Phenocryst
2. Vitreous
3. Vesicle
4. Cleavage
5. Twinning
6. Peat
1. a crystal on a rock that is especially conspicuous
2. glassy or looking like glass
3. air pockets
4. a sharp division
5. two or more crystals forming within each other.
6. the lowest grade of coal, with lowest carbon concentration
I'd make the following corrections:
4. Cleavage is the way the atoms in a crystal split along weaker surfaces.
5. Multiple crystals in different orientations, sharing a common surface
6. Peat is the precursor of coal, it is organic matter that has not yet been metamorphosed.
WEST WINDSOR-PLAINSBORO HIGH SCHOOL SOUTH '18
EMORY UNIVERSITY '22
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"One little Sciolyer left all alone,
He went out and hanged himself and then there were none."

Congratulations to WW-P South for winning 14th place at Nationals!

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Re: Rocks and Minerals B/C

Postby OrigamiPlanet » October 4th, 2017, 12:48 pm

1. Phenocryst
2. Vitreous
3. Vesicle
4. Cleavage
5. Twinning
6. Peat
1. a crystal on a rock that is especially conspicuous
2. glassy or looking like glass
3. air pockets
4. a sharp division
5. two or more crystals forming within each other.
6. the lowest grade of coal, with lowest carbon concentration
I'd make the following corrections:
4. Cleavage is the way the atoms in a crystal split along weaker surfaces.
5. Multiple crystals in different orientations, sharing a common surface
6. Peat is the precursor of coal, it is organic matter that has not yet been metamorphosed.
dxu46, you are still right to an extent, but I would prefer whythelongface's response with the last three as they are more accurate.
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Events: Battle at Valley Forge/MC Barons
Codebusters (3/3); Dynamic Planet (3/1); Astronomy (-/2)

Substitute in Event
Geologic Mapping (-/2)

Email me for anything!

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whythelongface
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Re: Rocks and Minerals B/C

Postby whythelongface » October 7th, 2017, 6:01 pm

New question:
1. What is the defining characteristic of sedimentary rocks in a low-energy environment of formation?
2. What is SEDEX?
3. From what mineral does Kaolinite form from?
4. What is a metamorphic facies? Give an example.
5. Explain fractional crystallization.
WEST WINDSOR-PLAINSBORO HIGH SCHOOL SOUTH '18
EMORY UNIVERSITY '22
SONT 2017 5th Place Medalist [Microbe Mission]

"One little Sciolyer left all alone,
He went out and hanged himself and then there were none."

Congratulations to WW-P South for winning 14th place at Nationals!

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Re: Rocks and Minerals B/C

Postby orangewhale » October 13th, 2017, 11:05 am

New question:
1. What is the defining characteristic of sedimentary rocks in a low-energy environment of formation?
2. What is SEDEX?
3. From what mineral does Kaolinite form from?
4. What is a metamorphic facies? Give an example.
5. Explain fractional crystallization.
1. Angular fragments
2. Sedimentary exhalative deposits 
3. Feldspar (not sure which type of feldspar)
4. Distinct mineral assemblages resulting from different formation environments. Example: greenschist facies result from low grade metamorphism
5. Since minerals crystallize at different temperatures, certain minerals will crystallize as a melt cools and separate from the melt. It's one way that magmatic differentiation takes place.

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whythelongface
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Re: Rocks and Minerals B/C

Postby whythelongface » October 13th, 2017, 7:14 pm

New question:
1. What is the defining characteristic of sedimentary rocks in a low-energy environment of formation?
2. What is SEDEX?
3. From what mineral does Kaolinite form from?
4. What is a metamorphic facies? Give an example.
5. Explain fractional crystallization.
1. Angular fragments
2. Sedimentary exhalative deposits 
3. Feldspar (not sure which type of feldspar)
4. Distinct mineral assemblages resulting from different formation environments. Example: greenschist facies result from low grade metamorphism
5. Since minerals crystallize at different temperatures, certain minerals will crystallize as a melt cools and separate from the melt. It's one way that magmatic differentiation takes place.
Except 1; The answer to that one was "small sediment size". Think about it this way: in a high-energy EoF, such as a stream bed, fine sediments would be washed out of the system. An example of a low-energy EoF would be the bottom of a very still lake, where silt could accumulate.
Your turn.
WEST WINDSOR-PLAINSBORO HIGH SCHOOL SOUTH '18
EMORY UNIVERSITY '22
SONT 2017 5th Place Medalist [Microbe Mission]

"One little Sciolyer left all alone,
He went out and hanged himself and then there were none."

Congratulations to WW-P South for winning 14th place at Nationals!

orangewhale
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Re: Rocks and Minerals B/C

Postby orangewhale » October 17th, 2017, 10:31 am

1. Describe idiochromatic, allochromatic, and pseudochromatic, and give an example of each.
2. What is the difference between a phenocryst and a porphyroblast?

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dxu46
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Re: Rocks and Minerals B/C

Postby dxu46 » November 9th, 2017, 5:11 pm

1. Describe idiochromatic, allochromatic, and pseudochromatic, and give an example of each.
2. What is the difference between a phenocryst and a porphyroblast?
1. Idiochromatic - in which a mineral is colored due to its natural properties (e.g. malachite)
    Allochromatic - in which a mineral is accidentally colored due to impurities (e.g. quartz)
    Pseudochromatic - in which a mineral undergoes a color change because of optical and/or physical properties (e.g. tarnished bornite)
2. Rock type (phenocryst is in igneous, porphyroblast is metamorphic)

orangewhale
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Re: Rocks and Minerals B/C

Postby orangewhale » December 1st, 2017, 2:52 pm

Correct, your turn.


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