Re: Rocks and Minerals Question Marathon
Posted: September 5th, 2011, 8:59 am
This is Amazonite(microcline). One big giveaway is the color, as well as the perfect cleavage and distinctive crystal pattern.
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Rocks and Minerals Question Marathon
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Re: Rocks and Minerals Question Marathon
Posted: September 5th, 2011, 9:00 am
Good job! And that's a great idea, by the wayiYOA wrote:For all id, I think we should also provide reasoning as to why we made that choice so it can be more helpful to people reviewing these questions.This is Amazonite(microcline). One big giveaway is the color, as well as the perfect cleavage and distinctive crystal pattern.
Re: Rocks and Minerals Question Marathon
Posted: September 5th, 2011, 9:35 am
[img]http://www.earthlightgems.com/sitebuildercontent/sitebuilderpictures/castletipselenite.JPG[/img] [img]http://www.mythnlynx.com/images/selenite1.jpg[/img] [img]http://www.crystalstargazer.com/seleniteSphere80mm4.0.JPG[/img] a) Identify it. b) In the last picture, what optical property is illustrated by the band of light which runs across the specimen.
Re: Rocks and Minerals Question Marathon
Posted: September 5th, 2011, 11:58 am
a) Identify it. Selenite [Gypsum] What tipped me off was luster and transparency; it's like sort of glossy, but not really... dunno how to explain :P b) In the last picture, what optical property is illustrated by the band of light which runs across the specimen. Cat's Eye
Re: Rocks and Minerals Question Marathon
Posted: September 5th, 2011, 12:05 pm
a is correct, b is very close; i think the formal term for it is chatoyancy.
Re: Rocks and Minerals Question Marathon
Posted: September 5th, 2011, 12:09 pm
"The term Cat's Eye, when used by itself as the name of a gemstone, can only be used to refer to a Cat's Eye Chrysoberyl. Any other stone exhibiting this phenomenon must have the stone's name after the Cat's Eye identifier, e.g., Cat's Eye Aquamarine."iYOA wrote:a is correct, b is very close; i think the formal term for it is chatoyancy.
This was on the wikipedia page for chatoyancy; cat's eye redirected there. Hopefully testwriters won't be that picky!
Re: Rocks and Minerals Question Marathon
Posted: September 7th, 2011, 12:54 pm
yep lol.
ur turn
ur turn
Re: Rocks and Minerals Question Marathon
Posted: September 7th, 2011, 1:04 pm
[img]http://www.irocks.com/db_pics/mdpics/MD-224741a.jpg[/img] 1. What is the mineral? 2. Name the group that this mineral belongs to.
Re: Rocks and Minerals Question Marathon
Posted: September 10th, 2011, 6:58 pm
If no one answers in the next 24 hours I will most likely give the answer in order to keep this thread from dying :3
Re: Rocks and Minerals Question Marathon
Posted: September 12th, 2011, 11:51 am
In order to keep this thread alive here is a new question.
What type of rock makes up Mammoth Caves?
What is its chemical composition?
What type of rock makes up Mammoth Caves?
What is its chemical composition?