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Dizzy

Green Obsidian?

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A friend of mine found this last Sat. while prospecting a local creek, an has asked me to help him identify the

substance. It was mixed among the river rocks that were lining the creekbed. It is transparent enough to shine a

flashlight or blacklight into and see the glow on the opposite side (about 9" across):

Philsrock062611001.jpg

Philsrock062611002.jpg

Here is a blacklight and regular flashlight shining through:

Philsrock062611009.jpg

The substance has a deep green color to it, and there are many small bubbles inside. I haven't tried to

flake off any of the material, but it looks like it would be very good for knapping. He also found

this odd material that appears to be somewhat fossilized, and includes what appears like quartz material

embedded in the stone:

Philsrock062611014.jpg

Any thoughts?

Dizz

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Check the hardness on the glassy stuff. Looks almost like glass slag.

The second one looks like fossilized Worm holes.

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Any thoughts?

Dizz

Does the green stuff streak?

Color?

Jim

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WOW Johnno, I never knew there was such an animal as green obsidian. It sure looks like slag glass. I've seen lots of black before but not green. Must be pretty much like man made glass.

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WOW Johnno, I never knew there was such an animal as green obsidian. It sure looks like slag glass. I've seen lots of black before but not green. Must be pretty much like man made glass.

Glass will be between 5 and 7 in hardness.

Obsidian above 5 - 7 most times. NO BUBBLES.

Yep, NO BUBBLES>

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Homefire, I was born an raised in the glass business back east thats why I tend to say glass it sure looks like it.

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Dizzy I have seen green obsidian and it is rare today. The green obsidian that I saw was in a necklace on an old lady. Her husband was a rockhound and found it in the 1950's. I agree that there should be no bubbles. I have some midnight lace that can be seen thru when slabbed and there is no bubbles. Slag glass is common and comes in many colors and is facetable as other glass is. It would be interesting what area you found the rocks in. If you are in California and east of sacramento there is a creek where my older cousin along with another older rockhound took a fairly large collection of lapidary rough and dumped it into a creek. He was starting in alzheimers and could not remember the location. I received the remainder of his collection that was not dumped. He decided it was the easiest way to dispose of a lot of rough rock without taking it to the dump. Sorry for the rambling but I would have to agree it is glass slag. Look at old bottles and you will see bubbles in them. Jerry

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Glass slag may be a very reasonable description, and thank you to Homefire for providing the

helpful data that obsidian wouldn't have the million bubbles..cause this thing is full of

'em. This was found creekside in a somewhat settled area here in WA. There are properties

bordering the creek, but the nearest buildings are 200-300 yds. distant from where this was

found. From what my neighbor described, it was pretty much a nightmare hacking their way

through the blackberries to get down to the creek, and it was in a narrow gully.

If he's home tomorrow I'll try a streak test and see what comes up, and I also plan to knock

off a chunk or five that I can use to try my hand at knapping some larger pieces. Can't

imagine where a chunk of glass this big would have gotten into that ravine, and from where

it would have come. Still, that makes the most sense at this point. I'll get some more pics

and a streak test and hopefully that will let us better determine it's true ID.

Thanks for all the great input.beer.gif

Mike

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Hi Guys-

I've seen a lot of obsidian in my time but never have I been able to see bubbles in it. Have also never been able to shine a light through a 9" thick piece of obsidian and observe a glow. While obsidian is translucent, you can only observe it around the edges. My guess is it's glass. :twocents: A streak test wouldn't tell you much since obsidian or glass doesn't leave a colored streak. The most you will see is just a white line.

Steve

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Hi Guys-

I've seen a lot of obsidian in my time but never have I been able to see bubbles in it. Have also never been able to shine a light through a 9" thick piece of obsidian and observe a glow. While obsidian is translucent, you can only observe it around the edges. My guess is it's glass. :twocents: A streak test wouldn't tell you much since obsidian or glass doesn't leave a colored streak. The most you will see is just a white line.

Steve

And what if it streaked green?

One of the signs obsidian has is flow bubbles

Sideromelane???

Jim

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And what if it streaked green?

One of the signs obsidian has is flow bubbles

Sideromelane???

Jim

I don't think any glass is going to streak other then white perhaps. Green glass shouldn't have a green streak anymore then black glass is going to have a black streak,etc.

Unlike the piece in the picture, all obsidian I have seen has been very dark and is hard to detect bubbles just by looking at it.

I looked up Sideromelane and it could very well be that but the color seems a little off.

Steve

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I don't think any glass is going to streak other then white perhaps. Green glass shouldn't have a green streak anymore then black glass is going to have a black streak,etc.

Unlike the piece in the picture, all obsidian I have seen has been very dark and is hard to detect bubbles just by looking at it.

I looked up Sideromelane and it could very well be that but the color seems a little off.

Steve

I think we need to know location! But then we would need geological data for that specific area! Hmmm. I have that for AZ but do not have the books for other states.

The assumption is what the streak resolves. You are assuming glass or obsidian. Yes, they will streak white (powder) but if it streaked green then it's something else (olivinite?). That is what I was getting at.

I was going to joke with Johnno about it being the olivine the was missing (fell out of) in the Tucson Ring! happy0193[1].gif

Jim

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It is green glass. You can see the surface where it was cast against in the second photo. Obsidian does not have bubbles like that.

Someone trying to fake a moldavite or something. Looks like an excellent piece to knock a few spalls off of and practice knapping.

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As I walked over to my neighbors I could see the crowded porch, meaning that a meeting of the CCOBS (Concrete Cranky Old Bastards Society) was in progress. With all the [wasted] years of wisdom present, we decided apply our cumulative knowledge to the problem.

Our final verdict was that the object was made up of melted net floats. Scratch test came up with no color at all. Back before plastic, they used glass balls as floats for fishing nets, marking crab pots, etc. An old fisherman among CCOBS members pointed this out to Phil and I just before he asked why we were lugging around a 20# chunk of molten crab float... :inocent:

Now, how/who melted them is another question that we'll never know the answer to, right along with how the heck the oversized paperweight wound up down in that deep ravine. :eee:

Few more pics:

062811011.jpg

062811005.jpg

062811002.jpg

We do appreciate all the helpful input, 'cause now Phil will quit walking around bragging that he had found a bowling ball sized Emerald. :hahaha:

Mike

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One thing I think of is that if it were natural , then there would be lots of float available, not just one big piece all by itself. I question the bubbles , as all the obsidian I have found, has not had bubbles...that I can recall

I think it is man made...

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Obsidian can have an occasional bubble but they are usually larger. Numerous small bubbles is indicative of glass.

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Yes, we've determined that it is melted glass, and was probably made using old green glass

crab pot and fishing net floats that were melted down.

Why they did it is a question for another day.

Mike

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I guess glass slag is the best bet, there is greenish glass formed from lightning strikes in sand (fulgurites), but those usually are smaller and more opaque. There also is at least one occasion where a meteorite blasted the Sahara desert and ended up forming green glass which is scattered in some area over there, but your piece would have had to have been created from a massive impact on the highest order for such a large piece. So, as I said, green glass slag sounds good to me.

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>>>>>>>>>I wrote all this went back and looked again and its green lol<<<<<<<<

Im not sure butt it could be blue amber :thumbsupanim or saphire that is a breathtaking piece. it is worth a grip either way on ebay check out raw or rough blue amber also google images is good for looking things up[raw blue amber ...raw saphire]

sold items, highest price first.they dont even have any that big :yesss: god must like whoever found it. look for more

.need help looking? really, I wouldnt tell anyone where its from till you get more.shoot it could be like a blue diamond lol .does if it changes color at different angles your stoked.tell your friend you thought he got it back already :brows: .lol just kidding. that other thing looks like under the ocean fossil.first pic is blue ambe.r second saphire :) well raw saphire and raw green amber? google images

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