bunnyfights
noticing nice landscape pebbles
Member since May 2022
Posts: 83
|
Post by bunnyfights on May 10, 2022 12:14:30 GMT -5
Same as always, Southern WI, and found with other sedimentary rocks. I have not found a lot of green stones in this local. Actually, this is my first one! Has a waxy feel but not as slick as the chert nodules. Looks to be softer than the chert as I can scratch the green areas with a common nail. Thanks for looking!
|
|
|
Post by vegasjames on May 10, 2022 21:00:10 GMT -5
Looks like an unakite (green epidote, pink orthoclase and white quartz).
|
|
|
Post by rmf on May 10, 2022 21:31:29 GMT -5
It looks a lot like serpentine but do not know of any in WI. May be epidote since there is metamorphics and igneous from some areas plus the residue from the glacier.
|
|
victor1941
fully equipped rock polisher
Member since November 2011
Posts: 1,975
|
Post by victor1941 on May 10, 2022 21:49:14 GMT -5
Is ricolite found in that area?
|
|
|
Post by fernwood on May 11, 2022 5:55:16 GMT -5
Maybe Unakite.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
|
Post by jamesp on May 11, 2022 13:31:36 GMT -5
Unakite marks the spot. Nice at that.
|
|
fuss
spending too much on rocks
Member since October 2018
Posts: 250
|
Post by fuss on May 11, 2022 18:37:42 GMT -5
I have not seen banded Unakite before, it's likely something else. here is an example of Unakite I picked from a lake Michigan beach the other day.
|
|
fuss
spending too much on rocks
Member since October 2018
Posts: 250
|
Post by fuss on May 11, 2022 18:41:52 GMT -5
And my Unakite sample and likely Bunnyfight's rock did not originate in Wisconsin, they got a ride here from Canada via the glacial express..
|
|
|
Post by Son Of Beach on May 11, 2022 19:07:18 GMT -5
I feel like what vegasjames said is true, there seems to be a sliding scale of what "unakite" is and where it begins and something like Episodite begins. The variation and patterns seem endless.
Spot the unakite
|
|
|
Post by vegasjames on May 11, 2022 19:49:39 GMT -5
I have not seen banded Unakite before, it's likely something else. here is an example of Unakite I picked from a lake Michigan beach the other day. I have found layered unakite before in Southern California.
|
|
nursetumbler
Cave Dweller
Member since February 2022
Posts: 928
|
Post by nursetumbler on May 12, 2022 3:07:18 GMT -5
I feel like what vegasjames said is true, there seems to be a sliding scale of what "unakite" is and where it begins and something like Episodite begins. The variation and patterns seem endless.
Spot the unakite
Son Of BeachBottom left corner, second up, partially covered?
|
|
nursetumbler
Cave Dweller
Member since February 2022
Posts: 928
|
Post by nursetumbler on May 12, 2022 3:08:05 GMT -5
I feel like what vegasjames said is true, there seems to be a sliding scale of what "unakite" is and where it begins and something like Episodite begins. The variation and patterns seem endless.
Spot the unakite
Son Of BeachBottom left corner, second up, partially covered? Actually I think it's all Unikite
|
|
fuss
spending too much on rocks
Member since October 2018
Posts: 250
|
Post by fuss on May 12, 2022 11:22:11 GMT -5
Unakite is hydrothermally altered Granite, how could it have layers? Getting back to the original post, able to be scratched by a "common nail" is interesting, and could mean Serpentine is a possibility like rmf said.
|
|
bunnyfights
noticing nice landscape pebbles
Member since May 2022
Posts: 83
|
Post by bunnyfights on May 12, 2022 13:19:12 GMT -5
Let me know if there is any other testing or information I can provide that might be of assistance.
|
|
|
Post by vegasjames on May 12, 2022 18:46:37 GMT -5
Unakite is hydrothermally altered Granite, how could it have layers? Getting back to the original post, able to be scratched by a "common nail" is interesting, and could mean Serpentine is a possibility like rmf said. Unakite is a metamorphic rock. A lot of metamorphic rocks are banded. I have banded versions of phyllite, schist, gneiss, marble and quartzite that are all metamorphic.
|
|
|
Post by vegasjames on May 12, 2022 21:20:00 GMT -5
|
|
fuss
spending too much on rocks
Member since October 2018
Posts: 250
|
Post by fuss on May 13, 2022 1:33:04 GMT -5
Those are interesting and attractive samples James. I have to question the ID of Unakite though, these samples appear much more interesting. Where were these found in So. CA? Good article on Unakite from Virginia. www.geol.umd.edu/undergraduate/paper/councell.pdf
|
|
|
Post by vegasjames on May 13, 2022 4:17:21 GMT -5
Those are interesting and attractive samples James. I have to question the ID of Unakite though, these samples appear much more interesting. Where were these found in So. CA? Good article on Unakite from Virginia. www.geol.umd.edu/undergraduate/paper/councell.pdf Out by Stateline. There is a lot of epidote with quartz in the area, as well as orthoclase and I have found a a couple types of unakite in the area.
|
|
|
Post by vegasjames on May 13, 2022 4:24:24 GMT -5
Those are interesting and attractive samples James. I have to question the ID of Unakite though, these samples appear much more interesting. Where were these found in So. CA? Good article on Unakite from Virginia. www.geol.umd.edu/undergraduate/paper/councell.pdf Here are some more examples:
A cab of the unakite from the area:
And a cab of the orthoclase from the area:
|
|
fuss
spending too much on rocks
Member since October 2018
Posts: 250
|
Post by fuss on May 14, 2022 9:03:11 GMT -5
Let me know if there is any other testing or information I can provide that might be of assistance. Bunnyfights, there are a few more tests you can do to help get a better idea of what you have, #1 you may not be interested in doing since it will be destructive but breaking the sample and photographing a fresh surface area from a few angles would be the most helpful.
#2 streak test #3 magnet test, see if one is attracted to your rock. #4 Acid drop test, check for bubbles or fizzing, (use Hydrochloric diluted to 10-20%). #5 you did a hardness already and since a nail scratched the green portion that suggests it is not Epidote. Try again in a few spots
|
|