Rocks and Minerals Question Marathon

starfield · Post by **starfield** » December 28th, 2011, 7:00 am

Wadhk wrote:
Answer (Click to Show Hidden Text)
Epidote? Monoclinic.

Correct!

Wadhk · Post by **Wadhk** » December 28th, 2011, 8:39 pm

hexagonaria · Post by **hexagonaria** » December 28th, 2011, 9:07 pm

answer (Click to Show Hidden Text)

some kind of off-color sodalite? My audubon guide says sodalite can be green as well as blue..

Wadhk · Post by **Wadhk** » December 29th, 2011, 12:35 pm

hexagonaria wrote:
answer (Click to Show Hidden Text)
some kind of off-color sodalite? My audubon guide says sodalite can be green as well as blue..

Correct! and yes, according to my notes sodalite can be blue, green, violet, etc.

hexagonaria · Post by **hexagonaria** » December 29th, 2011, 12:45 pm

1. Identify
2. What property is this sample exhibiting?

tornado guy · Post by **tornado guy** » December 29th, 2011, 12:47 pm

I think this is what it is (Click to Show Hidden Text)

Calcite

quizbowl · Post by **quizbowl** » December 29th, 2011, 2:45 pm

hexagonaria wrote:

1. Identify
2. What property is this sample exhibiting?

Hi (Click to Show Hidden Text)

Calcite
Birefringence

hexagonaria · Post by **hexagonaria** » December 29th, 2011, 4:06 pm

tornado guy was right about the calcite, but quizbowl answered it fully.
take it away quizbowl...

quizbowl · Post by **quizbowl** » December 29th, 2011, 5:57 pm

=D

Formation?

pinkyfinger · Post by **pinkyfinger** » December 30th, 2011, 12:52 am

Hmm (Click to Show Hidden Text)

It's probably either muscovite or a weird tremolite, but I'm leaning toward muscovite.

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