...try this one, and scroll down to Shaun Barrett's post.

The Mars Society messageboard topic URL is:
http://www.newmars.com/cgi-bin/ikonboard/ikonboard.cgi?s=f4b3783e6260d2dd74c63292bd647350;act=ST;f=24;t=155;st=210

I don't agree with Shaun Barrett's explanation, suggesting exotic crystals.

The pale lumpy, droopy material, near the RAT hole, obviously OOZED.
The question is when?

It's simple physics to state that when Spirit's RAT grinder made that hole in
that rock [PEACE rock?], heat was generated.
Cause and effect; did the grinding heat cause the drooping lumpy
[salty? frozen?] material to thaw and ooze, briefly flow syrup-like?

I'm standing by my hypothesis/speculation and saying YES!

Unless...JMS, Nick, or anyone else has a better explanation...I'd like to see it.

cheers.

Jacob