|
Post by paulshiroma on Feb 9, 2012 0:41:28 GMT -5
These are a couple of rocks that Andrew and I picked up out in Yermo back in November (http://forum.rocktumblinghobby.com/index.cgi?board=locations&action=display&thread=48850). They are really solid, dense pieces and seemed of retain really sharp edges along the fracture points. I had assumed that they were simply chert? but after a few cuts figured on asking the folks here for help with an ID: What's left of the first rock in question (several slabs went off to other folks) Slab: Rock 2: Cut end: Slabs: This is a rock that we pulled from the wash on the road just to the north of the Last Chance Canyon area that LarryS frequents (and may simply move to ). If anyone can help with an ID on this, I'd appreciate it. It's got a white/cream-colored material surrounding reddish/brown inclusions. We found several similar to this one. Thanks for the help! Paul
|
|
|
Post by johnjsgems on Feb 9, 2012 9:20:25 GMT -5
The first two are likely jasp-agate. The last one looks like some kind of opalite.
|
|
Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,466
|
Post by Sabre52 on Feb 9, 2012 9:56:36 GMT -5
Yep, so much volcanic ash to provide silica in those areas that there are a huge number of unnamed varieites of agate, jasper, jasp-agate and agate with opal inclusions. A lot of us give that stuff the generic designation of " petrified bog" as most specimens are some sort of volcanic ash/ mud/ sediment, often with organic inclusions that has been infused with silica......Mel
|
|
|
Post by johnjsgems on Feb 9, 2012 13:17:58 GMT -5
Mel is right (as usual). Pretty much all the jasp agate around Yermo/Calico is palm or bog based. Some of the bog material is really colorful. The palm fiber stuff is generally earth tones. Both will have interesting inclusions. Hard to picture that area as lake/swampy/palm forests looking at it now. When I first started going out to Newberry Springs in the 70's there was a cottonwood grove with standing water pools in the Mojave River about a 1/2 mile from where I live now. The neighbor that lived above it had a lot of arrowheads collected there. All were Calico/Yermo jasp-agates. Apparently the Indians rockhounded in the hills and camped by the water to make their points. Some time in the late 70's they opened the Silverwood Lake flood gates and the usually dry river ran bank to bank for a while. The Indian oasis was washed away, trees and all. This was a long way of saying yes, the rocks from there flake with sharp edges.
|
|
|
Post by paulshiroma on Feb 9, 2012 23:54:34 GMT -5
Got it, thanks for the help with this guys. Thanks for the extensive explanation, John
|
|