|
Post by geoff on Jul 18, 2012 11:50:27 GMT -5
Ok, I got one for you. I plucked this out of the Jack river, a couple miles East of Cantwell on the Denali Highway. This is the area where rhodonite can be found. I found this rock that I initially thought had orbiculars on it. Brought it home and tried my hardness picks on it. Well, the pink was too weathered to test, just kept breaking apart so I cut a piece off. Thats when I saw that it wasn't orbiculars or tubes. Everything comes out to right around 7. Streak is white. No difference in hardness or streak for any of the different colors. I brought it to the guy who knows more about Alaskan rocks than anyone, and I stumped him too. It does not react to HCl, and under magnification, the gray/green is agate. The pink and white is the same material, but the pink appears to be the result of preferential staining. The fracture on the weathered pink/white is square, but when you make a fresh fracture, it is choncoidal. Attachments:
|
|
|
Post by geoff on Jul 18, 2012 11:51:38 GMT -5
Photobucket s broken Attachments:
|
|
|
Post by geoff on Jul 18, 2012 11:52:23 GMT -5
blah Attachments:
|
|
|
Post by jakesrocks on Jul 18, 2012 12:42:02 GMT -5
Sounds like one for the Mindat folks. www.mindat.org/It will be interesting to hear what you find out. Keep us posted.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Jul 18, 2012 15:41:39 GMT -5
Looks and sounds like agate to me, as there seem to be at least one white fortification line between the grayish chalcedony and reddish/greenish areas. Were it not for the green, the outside recalls some youngite agate nodules. The foliate splitting on the orb-like formations might indicate some sort of petrified/agatized root or gall. Interesting find!
|
|
Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,466
|
Post by Sabre52 on Jul 19, 2012 19:01:31 GMT -5
I'm thnking it's an agate pseudomorph after one of the minerals with rosette form crystal clusters, maybe barite or aragonite....Mel
|
|
|
Post by paulshiroma on Jul 19, 2012 21:55:43 GMT -5
Interesting piece, Geoff... got me!
|
|