Is this Slag Glass or Obsidian?

Hi all, been doing lots of searching trying to figure out what this is and how old it could be.

My son found these at a dig site in Newport, Kentucky right along the Ohio river 30 feet down in the ground. At first we thought it could be Obsidian but also could be Slag Glass. If Slag Glass, how old could this possibly be? It's very pretty and he said there are some really big pieces there and will be bringing them home.

Thoughts and thanks for any input!

 

Is the color red? purple?
I've only seen black and chocolate obsidian. So I'm leaning toward glass.
Not volcanic glass rock.

 

Thanks!! I just did that

 

It has lots of color for sure, some even rainbow. I'm leaning towards glass too since there are no volcanoes in KY unless someone brought them there and they were left many many years ago since they are 30 feet down in the ground.

 

This article does mention red, but says it is rare.
https://geology.com/rocks/obsidian.shtml

Wiki doesn't mention red.
https://en.wikipedia.org/wiki/Obsidian

 

This very much reminds me of the glass they used in electric fireplaces of the 1920's-30's. It was used to simulate coal and there would have been a light bulb and fan to create the illusion of glowing coal embers.

 

are there known old defunct glass furnaces in the general area? If it's glass, it would more likely be cullet than slag glass.

 

That I do not know...If there was, not anymore since this was found literally very close to the river. There was a major flood back in 1937 but I'm not from that area so I really do not know the history of Newport, Kentucky. Here is a picture showing just how close to the river that they are digging.

 

Also, he said there are some really big pieces and will be bringing those home.

 

That is very interesting!

 

I actually just sent the KGS an email with photos, maybe they can help shed some light. Whatever they are, they are very pretty and not light.

 

Welcome, Renee. Put me in the slag glass camp too, for all the reasons already mentioned & also because it was found by a river, a good place to be if you're manufacturing anything that requires power. I have to this day, many, many days later than the day I got it, a piece of material found by a river during a grade school outing when we were supposed to be looking for fossils. Found plenty of those too, but the pinkish 'stone' I also found seemed the most beautiful, magical thing ever dug out of sand (another thing good to have handy if you're making glass). Later confirmed by a natural history museum mineralogist to be glass. Think the color has faded a little over the decades.

 

Not sure I would tell them you dug it up or where.
They may confiscate it. I'm in CA so pardon my mindset.

 

This is what I found out:

Here’s what one of our geologists said…and others agree with him:


“Most likely glass slag from one of the steel plants along the Ohio River, since it was found near Cincinnati.”


We have received photos of very similar specimens in the past, some of them from the area around Mammoth Cave, where some people find them and try to sell them, passing them off as “cave glass.”