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Re: Rocks and Minerals B/C

Posted: March 14th, 2018, 5:24 pm
by karanbe123
1. Name the common mineral assemblages of the following metamorphic facies:
a. Greenschist
b. Blueschist
c. Eclogite
d. Granulite
2. What is an QAPF diagram used for? What does it stand for?
3. What is the name of the platy variety of albite?
4. Explain the etymology of "feldspar".
5. What is the difference between the two groups of garnet? Which group does almandine belong in?
1. a. chlorite + albite + epidote ± actinolite, quartz
b. glaucophane + lawsonite + chlorite + sphene ± epidote ± phengite ± paragonite, omphacite
c. omphacite + garnet ± kyanite, quartz, hornblende, zoisite
d. orthopyroxene + clinopyroxene + hornblende + plagioclase ± biotite
2. Stands for Quartz,Alkali feldspar, Plagioclase, Feldspathoid. It's used to classify plutonic and sometimes volcanic rocks if mineralogical compositions were already determined.
3. cleavelandite?
4. The modern name probably derives from terms used by German miners. "Feld" is an old name for hard rocks and "spat" referred to any rock or mineral that if stroked by a hammer forms plain surfaces (as said feldspars indeed show perfect cleavage).
5. The first group has Aluminum as the second element(pyralspite) and the second group has Aluminum as the first element(Ugrandite). Almandine belongs to the pyralspite group.

Re: Rocks and Minerals B/C

Posted: March 21st, 2018, 12:42 pm
by whythelongface
That's correct, no idea why I didn't say so earlier. Except I heard "feldspat" derived from "field-stone", meaning either unwanted tailings to be discarded in the field, or as a stone commonly found in tilled fields...

Re: Rocks and Minerals B/C

Posted: March 21st, 2018, 3:34 pm
by ScottMaurer19
That's correct, no idea why I didn't say so earlier. Except I heard "feldspat" derived from "field-stone", meaning either unwanted tailings to be discarded in the field, or as a stone commonly found in tilled fields...
That's what I remember as well

Re: Rocks and Minerals B/C

Posted: April 11th, 2018, 7:28 pm
by dxu46
[img]https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRDHrKEU01AGGktGy8NTBQd21rz6E5BV1niWQBCIQZMyuACNQSm9g[/img][img]https://i.ebayimg.com/images/g/K3wAAOSwzgRWyMlV/s-l300.jpg[/img][img]https://amedia.britannica.com/700x450/94/7794-004-64899190.jpg[/img]
1. All three of these specimens are varieties of what mineral?
2. Name the three varieties in order from left to right.
3. Why do these varieties occur? (specifically, what elements make the mineral turn different colors?)
4. What crystal system does this mineral crystallize into?
5. Define triboluminiscence.
6. Is this mineral triboluminiscent?
7. Define piezoelectricity.
8. Is this mineral piezoelectric?

Re: Rocks and Minerals B/C

Posted: April 12th, 2018, 6:56 am
by Etan
Here's a question!

Image

1.What is the chemical composition of this specimen?
2.What mineral does this specimen form from?
3.List three other minerals that have the same classification

btw sorry that I takes up the whole screen I don't know how to do the reveal button thing

Re: Rocks and Minerals B/C

Posted: April 12th, 2018, 8:55 am
by dxu46
Here's a question!

Image

1.What is the chemical composition of this specimen?
2.What mineral does this specimen form from?
3.List three other minerals that have the same classification

btw sorry that I takes up the whole screen I don't know how to do the reveal button thing
1. SiO2
2. It doesn't form from a mineral as it is a mineral, but I'm assuming you meant "what mineral is this a variety of," in which it is Quartz.
3. Amethyst, Agate, Chalcedony
Also someone answer my question above.

Re: Rocks and Minerals B/C

Posted: April 12th, 2018, 9:43 am
by ScottMaurer19
Here's a question!

Image

1.What is the chemical composition of this specimen?
2.What mineral does this specimen form from?
3.List three other minerals that have the same classification

btw sorry that I takes up the whole screen I don't know how to do the reveal button thing
1. SiO2
2. It doesn't form from a mineral as it is a mineral, but I'm assuming you meant "what mineral is this a variety of," in which it is Quartz.
3. Amethyst, Agate, Chalcedony
Also someone answer my question above.
Citrine forms from amethyst when it is heated/heat treated

Re: Rocks and Minerals B/C

Posted: April 12th, 2018, 1:23 pm
by dxu46
Here's a question!

Image

1.What is the chemical composition of this specimen?
2.What mineral does this specimen form from?
3.List three other minerals that have the same classification

btw sorry that I takes up the whole screen I don't know how to do the reveal button thing
1. SiO2
2. It doesn't form from a mineral as it is a mineral, but I'm assuming you meant "what mineral is this a variety of," in which it is Quartz.
3. Amethyst, Agate, Chalcedony
Also someone answer my question above.
Citrine forms from amethyst when it is heated/heat treated
No, I understand that, but it doesn't form from amethyst per se, as heat treating isn't creating a whole different mineral (kind of, but no).

Also
[img]https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRDHrKEU01AGGktGy8NTBQd21rz6E5BV1niWQBCIQZMyuACNQSm9g[/img][img]https://i.ebayimg.com/images/g/K3wAAOSwzgRWyMlV/s-l300.jpg[/img][img]https://amedia.britannica.com/700x450/94/7794-004-64899190.jpg[/img]
1. All three of these specimens are varieties of what mineral?
2. Name the three varieties in order from left to right.
3. Why do these varieties occur? (specifically, what elements make the mineral turn different colors?)
4. What crystal system does this mineral crystallize into?
5. Define triboluminiscence.
6. Is this mineral triboluminiscent?
7. Define piezoelectricity.
8. Is this mineral piezoelectric?

Re: Rocks and Minerals B/C

Posted: April 14th, 2018, 10:52 am
by whythelongface
[img]https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRDHrKEU01AGGktGy8NTBQd21rz6E5BV1niWQBCIQZMyuACNQSm9g[/img][img]https://i.ebayimg.com/images/g/K3wAAOSwzgRWyMlV/s-l300.jpg[/img][img]https://amedia.britannica.com/700x450/94/7794-004-64899190.jpg[/img]
1. All three of these specimens are varieties of what mineral?
2. Name the three varieties in order from left to right.
3. Why do these varieties occur? (specifically, what elements make the mineral turn different colors?)
4. What crystal system does this mineral crystallize into?
5. Define triboluminiscence.
6. Is this mineral triboluminiscent?
7. Define piezoelectricity.
8. Is this mineral piezoelectric?
To my knowledge the rightmost two specimens are of the same variety.

Re: Rocks and Minerals B/C

Posted: April 14th, 2018, 11:25 am
by dxu46
[img]https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRDHrKEU01AGGktGy8NTBQd21rz6E5BV1niWQBCIQZMyuACNQSm9g[/img][img]https://i.ebayimg.com/images/g/K3wAAOSwzgRWyMlV/s-l300.jpg[/img][img]https://amedia.britannica.com/700x450/94/7794-004-64899190.jpg[/img]
1. All three of these specimens are varieties of what mineral?
2. Name the three varieties in order from left to right.
3. Why do these varieties occur? (specifically, what elements make the mineral turn different colors?)
4. What crystal system does this mineral crystallize into?
5. Define triboluminiscence.
6. Is this mineral triboluminiscent?
7. Define piezoelectricity.
8. Is this mineral piezoelectric?
To my knowledge the rightmost two specimens are of the same variety.
The one on the bottom is supposed to be translucent-transparent, slightly brown. I couldn't find a good picture, sorry.