The Naked Scientists

The Naked Scientists Forum

Author Topic: Can you identify these rocks/minerals?  (Read 4728 times)

Offline paular

  • First timers
  • *
  • Posts: 1
    • View Profile
Can you identify these rocks/minerals?
« on: 05/12/2008 21:28:58 »
The picture isn't that good, but I was wondering if anyone recognized any of the material in the picture?


 

Offline RD

  • Neilep Level Member
  • ******
  • Posts: 8131
  • Thanked: 53 times
    • View Profile
Can you identify these rocks/minerals?
« Reply #1 on: 06/12/2008 14:51:21 »
Feldspar ?


 

                                                                            http://en.wikipedia.org/wiki/Feldspar
 

Offline frethack

  • Sr. Member
  • ****
  • Posts: 394
    • View Profile
Can you identify these rocks/minerals?
« Reply #2 on: 06/12/2008 18:06:09 »
Maybe post some closeups of some individual rocks?
 

Offline JimBob

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 6564
  • Thanked: 7 times
  • Moderator
    • View Profile
Can you identify these rocks/minerals?
« Reply #3 on: 07/12/2008 03:29:39 »
The upper right hand picture is almost assuredly a rholyte from central Texas called Llanite. I have specimens that are identical to it. The blue is a piece of VERY RARE square, blue quarts so I doubt that is what is in the bag. The grey stuff in the bag is likely galena - lead. The White rock could well be Plagioclase-rich granite - K-Feldspar in a granite.

I agree with the green guy - open the bags and get close-ups of everything.
 

Offline Bass

  • Neilep Level Member
  • ******
  • Posts: 1340
  • Thanked: 5 times
    • View Profile
Can you identify these rocks/minerals?
« Reply #4 on: 07/12/2008 04:42:27 »
The grey stuff in the bag is likely galena - lead.

Looks like glass in both bags to me ???

Quote
The White rock could well be Plagioclase-rich granite - K-Feldspar in a granite.

So which is it- plagioclase or K-feldspar??
Plagioclase refers to a group of feldspars that form a solid solution series from Na rich to Ca rich- but no potassium (K).  K-feldspar (or potassium feldspar) is a different mineral, though the two commonly coexist in igneous rocks.

Probably K-feldspar in a pegmatite.

I have no idea whether the gray-green blob is a rock or bunch of clay?

Better photos and a few descriptions would certainly help.
 

The Naked Scientists Forum

Can you identify these rocks/minerals?
« Reply #4 on: 07/12/2008 04:42:27 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums