Can you identify these rocks/minerals?

  • 4 Replies
  • 4756 Views

0 Members and 1 Guest are viewing this topic.

*

Offline paular

  • First timers
  • *
  • 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?
[attachment=5544]

*

Offline RD

  • Neilep Level Member
  • ******
  • 8175
    • View Profile
Can you identify these rocks/minerals?
« Reply #1 on: 06/12/2008 14:51:21 »
Feldspar ?

[attachment=5592]
 

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

*

Offline frethack

  • Sr. Member
  • ****
  • 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?
frethack

"Flying is learning how to throw yourself at the ground and miss."
- Douglas Adams

*

Offline JimBob

  • Global Moderator
  • Neilep Level Member
  • *****
  • 6564
  • 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.
The mind is like a parachute. It works best when open.  -- A. Einstein

*

Offline Bass

  • Neilep Level Member
  • ******
  • 1340
    • 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.
Old enough to have a grandson
Slow enough to study rocks
Thirsty enough to find a pub