The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Jun 26, 2014 12:39:55 GMT -5
Ok, this thread has been going on too long without me putting in my 2 cents!!!! Luckily for all of you my soapbox is out being cleaned too !!!! Anyways... last year I went out to Alabama & Georgia and found along the dirt roadsides lots of what at first I thought was Green Obsidian and later found out it was slag glass that was added to the road beds when the dirt roads were made!! Also, when we visited one of the last of the cold forges left in Alabama, we found all along the trails and around the forge (made of Hematite... very cool and huge!!) more glass strewn all over! The slag was a byproduct of the forge process and was considered useless so it was added to the road construction to help firm up the roads, no longer used due to the flat tires it caused. but anyways I brought back a few pounds of pieces and most of it shattered when I tried to cut it, however I did manage to get 1 slab of it and it is making an interesting looking mid to dark green cab... I'll post some pics when done!! I thought it was green OB.... I was soooooo excited by the idea at the time!!  |
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Post by jakesrocks on Jun 26, 2014 12:50:08 GMT -5
Phil, while stationed in Spain I had a friend who used to buy huge blocks of pumice. He carved them into castles and all sorts of things, using only a pocket knife, a couple of sharpened screwdrivers and a few home made carving tools.
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on Jun 26, 2014 12:56:20 GMT -5
If it matters anymore, there is a way to tell glass from obsidian, but it's totally destructive of the piece being tested. I knap, and have done lots of obsidian, and glass also. obsidian is formed under pressure during a volcanic flow. Glass is formed sans pressure. If glass is placed in a kiln, as in fusing, it just slumps and melts into a pool, puddle, etc. If obsidian is placed in a kiln, you'd better have a very small amount in a large disposable container. When heated, the pressure is released, the obsidian starts to foam, and expands immensely, releasing all that pressure and ending up like a huge wispy chunk of glassine foam, tan in color regardless of what color it started out as. Like tufa, but not tufa. Near me, about 60 miles away, is a volcanic crater and ridge "mountain" where this happened, and the resulting "rocks" actually float on water, slowly becoming water logged, when they finally sink. It's called Valles Caldera. Beautiful country! It's great for using as a scrubbing block, some ladies use it to remove unsightly dry skin around their ankles and feet, it's great for cleaning a toilet bowl, and its a neat conversation piece. Lat time I was up there,I gathered a bucket full to show kids how rocks can float. BTW, I agree, that photo was of glass, not obsidian. Sounds like perlite pumice [thanks Don, I had the wrong word!] to me. Also explains why tumbled obsidian explodes the barrels sometimes. At what temp would this transformation happen? I have to much obsidian and would rather scrub toilets with it! lol |
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Post by kap on Jun 26, 2014 14:52:50 GMT -5
;0
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Post by rockpickerforever on Jun 26, 2014 15:52:46 GMT -5
These two pics of obsidian (I know it's not glass) are for Mike Fossilman . Picked up a couple chunks of green, yes, GREEN obsidian in Quartzsite in January. I think I cut it at about the right angle, just on one face to see how it went. First pic (mostly) flat, but can still see the green. Taken in bright sunlight. 
Second pic tilted just a bit to the proper angle. No color correction or adjustment on either of these pics.
This stuff just glows green, almost looks radioactive, lol. There are a few spots of the perlite/pumice (makes me think of puffed wheat), and a few empty gas bubbles I'll have to work around. As such, no good for knapping. If I had the skilz, I'd carve it - maybe. Will most likely do some cabs. |
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Post by phil on Jun 26, 2014 17:35:50 GMT -5
Ok, this thread has been going on too long without me putting in my 2 cents!!!! Luckily for all of you my soapbox is out being cleaned too !!!! Anyways... last year I went out to Alabama & Georgia and found along the dirt roadsides lots of what at first I thought was Green Obsidian and later found out it was slag glass that was added to the road beds when the dirt roads were made!! Also, when we visited one of the last of the cold forges left in Alabama, we found all along the trails and around the forge (made of Hematite... very cool and huge!!) more glass strewn all over! The slag was a byproduct of the forge process and was considered useless so it was added to the road construction to help firm up the roads, no longer used due to the flat tires it caused. but anyways I brought back a few pounds of pieces and most of it shattered when I tried to cut it, however I did manage to get 1 slab of it and it is making an interesting looking mid to dark green cab... I'll post some pics when done!! I thought it was green OB.... I was soooooo excited by the idea at the time!! Did you anneal it? |
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Post by phil on Jun 26, 2014 17:39:53 GMT -5
At what temp would this transformation happen? I have to much obsidian and would rather scrub toilets with it! lol No idea. When it goes, it goes quickly, and I don't have a kiln that I'm willing to destroy. Once it goes, whatever container it was in is toast. Next time I'm up that way. (no idea when), if I remember, (big if!) I can collect some for you if you want some. There's about 1/8th mile of road where it's always rolling onto the roadway. I don't think it's called pumice, but I forget the name. |
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on Jun 26, 2014 18:31:32 GMT -5
perlite?
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Post by phil on Jun 26, 2014 20:30:45 GMT -5
i'll try and find out.
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donkeyrokman
noticing nice landscape pebbles
Member since June 2014
Posts: 78 
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Post by donkeyrokman on Jun 27, 2014 10:31:03 GMT -5
Yeah, Scott, can you imagine that? Hard to believe, lol. Hey, donkeyrokman, nothing wrong with pulling up the old stuff, lots of old threads are worth revisiting. Are you going to introduce yourself? Welcome to the show! Jean Hey Jean, Thanks for the greeting. I'm a full time, professional artist/stone carver. I work with slate, sandstone, marble, rhyolite, quartzite, and a few others. Next year will mark thirty years in the business of producing art for a living. Rock hound since, well, birth.  You've got a great site here. I love that so many members are eager to help when there's a question, and that they're excited about other member's successes. Very cool. Regards, Don |
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donkeyrokman
noticing nice landscape pebbles
Member since June 2014
Posts: 78
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Post by donkeyrokman on Jun 27, 2014 10:36:33 GMT -5
I'd also like to mention there are some unscrupulous characters at the Tucson show that are selling "Green Obsidian" for big bucks, along with a BS story (no documentation) about having it tested by experts, when in fact it is simply slag glass. (I have a friend who got taken by these criminals, so I got a good look at this stuff. No question it's slag.)
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Post by rockpickerforever on Jun 27, 2014 11:00:12 GMT -5
Don, thanks for the intro! Ah, another Libra, I see. What part of the country are you from? I'm guessing the southwest, since you seem to frequent Quartzsite. Have been there often enough to know that unless you are informed, there are many unscrupulous sellers that will take advantage of you in a heartbeat (but not our Tony catmandewe of Idaho Rocks, or John johnjsgems, though!). I know there are many more forum members that are regulars in Quartzsite. Cool background you have. Great to be a successful artist, not a starving one. I think you will enjoy the warm folks (for the most part, lol) here, and the knowledge they are so willing to share. Jean |
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donkeyrokman
noticing nice landscape pebbles
Member since June 2014
Posts: 78
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Post by donkeyrokman on Jun 27, 2014 12:52:22 GMT -5
Don, thanks for the intro! Ah, another Libra, I see. What part of the country are you from? I'm guessing the southwest, since you seem to frequent Quartzsite. Have been there often enough to know that unless you are informed, there are many unscrupulous sellers that will take advantage of you in a heartbeat (but not our Tony catmandewe of Idaho Rocks, or John johnjsgems, though!). I know there are many more forum members that are regulars in Quartzsite. Cool background you have. Great to be a successful artist, not a starving one. I think you will enjoy the warm folks (for the most part, lol) here, and the knowledge they are so willing to share. Jean Jean, All over. Arizona, California, Texas. Oregon for the last ten years. Grew up collecting fossils in Ohio. Already enjoying it here.  Don |
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Post by radio on Jun 27, 2014 17:54:57 GMT -5
The white area on it along with the transparancy says glass to me. I have seen similar slag glass, but never seen a white inclusion like that in obsidian
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Post by rockpickerforever on Jun 28, 2014 9:02:51 GMT -5
It is obsidian to the best of my knowledge. Looks just like a lot of the rainbow types that I have, only green. Don't think that slag glass has schiller. Guess the photos really don't do it justice. Will have to bring it with me to Quartzite next year, so it can be examined in hand.
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The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Jun 29, 2014 19:07:09 GMT -5
Ok, this thread has been going on too long without me putting in my 2 cents!!!! Luckily for all of you my soapbox is out being cleaned too !!!! Anyways... last year I went out to Alabama & Georgia and found along the dirt roadsides lots of what at first I thought was Green Obsidian and later found out it was slag glass that was added to the road beds when the dirt roads were made!! Also, when we visited one of the last of the cold forges left in Alabama, we found all along the trails and around the forge (made of Hematite... very cool and huge!!) more glass strewn all over! The slag was a byproduct of the forge process and was considered useless so it was added to the road construction to help firm up the roads, no longer used due to the flat tires it caused. but anyways I brought back a few pounds of pieces and most of it shattered when I tried to cut it, however I did manage to get 1 slab of it and it is making an interesting looking mid to dark green cab... I'll post some pics when done!! I thought it was green OB.... I was soooooo excited by the idea at the time!! Did you anneal it? No, the glass is as I found it, the piece I am working on is coming along nicely, but slowly, I hope to have it in polish on Wednesday. I'll post some rough and finished pics of the material when I'm done. I didn't want to change/heat it, just wanted to see if it could be worked as is. |
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Post by Pat on Sept 4, 2017 17:12:24 GMT -5
Tommy could you fix the photos in this thread? Thanks.
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Tommy
Administrator 
Member since January 2013
Posts: 12,989
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Post by Tommy on Sept 4, 2017 17:58:47 GMT -5
Tommy could you fix the photos in this thread? Thanks. The only ones I could fix were the the three in your post on page 1. Everything else is permanently broken at the host - meaning they were deleted off of photobucket and flickr by the user. |
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tarasparkle
off to a rocking start
Member since April 2018
Posts: 1
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Post by tarasparkle on Apr 27, 2018 4:50:39 GMT -5
Hi I have blue obsidian and just want to confirm it is blue obsidian? How can I post a photo please?
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Post by rockjunquie on Apr 27, 2018 6:19:10 GMT -5
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