green volcanic glass?

[mungeclimber]

This has been mentioned as being at Pinnacles, but I'm not sure what it is referring to.

Anyone seen this before?

[JC w KC redux]

I've got an old field guide around here somewhere that gives some pretty good geologic background on the Monument.
I believe the rock you are referring to is called Perlite and it is green and glassy.
If I remember correctly we used to walk up Condor Gulch to a sizeable outcrop when we did a geologic mapping exercise with our West Valley classes. I'll email my colleague over there and get him to email me the guide.

[JC w KC redux]

I found it and I was right - at least partially.
The perlite is a hydrated volcanic glass that can be green when fresh and weathers to grayish hues.
There is also a lapilli tuff that's green.
I'll scan some stuff and send you a PM probably tomorrow...
I've got a map that shows where the different rock types are exposed - it's pretty cool.

[mungeclimber]

sweet, thx!!