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Rocks and Minerals Question Marathon

Posted: August 28th, 2011, 6:53 pm
by Jim_R
This thread is for asking questions about specific Rocks and Minerals.
It will consist of someone posting a picture of a rock or a mineral, or posting any question regarding to this event. People will post their guesses here (preferably you should hide your answer) - if they are right, it becomes their turn to post.
I'll start:
You have a magma that is at very high temperature and pressure.

What minerals would the rock formed from this magma have if it was intruded into the earth?

What minerals would it have if it was extruded onto the surface of the earth?

What would be the difference in these rocks?

Re: Rocks and Minerals Question Marathon

Posted: August 29th, 2011, 1:24 pm
by XXGeneration
Is there anything about the composition of the magma?

If not, then:
If the magma were extruded, then the rock formed would be basalt because usually at high temperatures magma is basaltic. Basalt is composed of sodium plagioclase minerals, pyroxene, and olivine.

If the magma were intruded, then the rock formed would be gabbro; gabbro is composed of calcium plagioclase feldspars, pyroxene, and olivine.

The main difference is that basalt has a fine texture while gabbro is much coarser; the crystal sizes are different because of the difference in cooling duration.
Does anyone know how to stop the space right after the spoiler?

Re: Rocks and Minerals Question Marathon

Posted: August 30th, 2011, 8:35 am
by XXGeneration
I'll assume that I'm right and post a question 2
[img]http://www1.newark.ohio-state.edu/Professional/OSU/Faculty/jstjohn/Minerals/Grosbeak-Lake-halite.jpg[/img]
[img]http://t1.gstatic.com/images?q=tbn:ANd9GcTpWOcgnAhdhPcEwwdoFLHyo2PSQyMXUXzjWhUwFn5macawgtoM[/img]
1. Identify the mineral
2. This mineral is a source of what common household item?

Re: Rocks and Minerals Question Marathon

Posted: August 31st, 2011, 7:27 am
by JSGandora
I'm not doing R/M but the answers are:
1. Halite
2. Tastifier for French Fries (you get the picture)
Identify this rock:
[img]http://www.mii.org/Minerals/Minpics1/Marble.jpg[/img]

Re: Rocks and Minerals Question Marathon

Posted: August 31st, 2011, 7:39 am
by XXGeneration
Marble
[img]http://www.minerals.net/MineralImages/ulexite1.jpg[/img]
1. Identify this mineral
2. What nickname does this mineral have and why is this nickname given?

Re: Rocks and Minerals Question Marathon

Posted: September 1st, 2011, 11:11 am
by quizbowl
1. Ulexite
2. It is nicknamed TV stone due to its optical characteristics, with the fibers acting like optical fibers
By the way, you're supposed to wait a bit before posting your next question.  You might not be 100% correct or someone might be looking or a different answer

Re: Rocks and Minerals Question Marathon

Posted: September 1st, 2011, 1:34 pm
by XXGeneration
1. Ulexite
2. It is nicknamed TV stone due to its optical characteristics, with the fibers acting like optical fibers
By the way, you're supposed to wait a bit before posting your next question.  You might not be 100% correct or someone might be looking or a different answer
I'm sorry; in my eagerness to keep this thread from dying I just posted the next question.

By the way, you are correct.

Re: Rocks and Minerals Question Marathon

Posted: September 1st, 2011, 2:09 pm
by JSGandora
Marble
[img]http://www.minerals.net/MineralImages/ulexite1.jpg[/img]
1. Identify this mineral
2. What nickname does this mineral have and why is this nickname given?
You already know through gmail, but you are correct. This is so that everyone knows.

Re: Rocks and Minerals Question Marathon

Posted: September 1st, 2011, 2:53 pm
by quizbowl
yay!
Image
Chemical formula?

Re: Rocks and Minerals Question Marathon

Posted: September 1st, 2011, 3:02 pm
by XXGeneration
yay!
Image
Chemical formula?
I believe the mineral is Bornite; the formula for Bornite is Cu2FeS4.