What kind of rocks are these?

[WhiteRabbit1220]

I found them in Middle Tennessee. They were very concentrated in the area. They're black, with blue/purple or green tints, some more than others. Some are smooth and feel just like glass and some are rough/bumpy. Any input would be much appreciated. They look better in person.

 

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[Indian Steve]

I'm thinking that they are slag from an old iron furnace. I've found similar around and old iron furnace

 

[WhiteRabbit1220]

Okay, I was wondering that myself but thanks for confirming. I like them anyway.

 

[Indian Steve]

When I first found the ones that I found, I thought I was finding obsidian but there isn't any obsidian in Virginia. They are still cool!

 

[MR.CREED]

When I first found the ones that I found, I thought I was finding obsidian but there isn't any obsidian in Virginia. They are still cool!

There is obsidian in va I have some and send it to a geologist

 

[Red-Coat]

When I first found the ones that I found, I thought I was finding obsidian but there isn't any obsidian in Virginia. They are still cool!

There is obsidian in va I have some and send it to a geologist

I would agree that's slag... and also agree that Virginia does have obsidian.

The state has two ‘young’ volcanoes in the Appalachian Mountains: at Mole Hill and at Trimble Knob. The sources exist today as the heavily-eroded necks and remnants of the interior of primeval volcanoes. They do nevertheless have the remains of gaseous vents within which there is still unweathered obsidian, first identified and documented by geologists in 1899. A few of the obsidian artefacts found in Virginia have definitively been attributed to these sources, so ancient people must have discovered them. Also, the Smith and Dan Rivers that originate from the Blue Ridge and Appalachian Mountains carry occasional pieces of obsidian from these sources into the Piedmont along the NC/VA border and that’s where many of the obsidian artefacts have been found., typically dating between 2,000 – 10,000 BC, which is well before the believed lithic trading networks existed.

 

[wizenedmandrill]

I would agree that's slag... and also agree that Virginia does have obsidian.

The state has two ‘young’ volcanoes in the Appalachian Mountains: at Mole Hill and at Trimble Knob. The sources exist today as the heavily-eroded necks and remnants of the interior of primeval volcanoes. They do nevertheless have the remains of gaseous vents within which there is still unweathered obsidian, first identified and documented by geologists in 1899. A few of the obsidian artefacts found in Virginia have definitively been attributed to these sources, so ancient people must have discovered them. Also, the Smith and Dan Rivers that originate from the Blue Ridge and Appalachian Mountains carry occasional pieces of obsidian from these sources into the Piedmont along the NC/VA border and that’s where many of the obsidian artefacts have been found., typically dating between 2,000 – 10,000 BC, which is well before the believed lithic trading networks existed.

Is there a way to tell it's slag and not obsidian just by looking at it, or do location and other factors come into play?

 

[ToddsPoint]

I was on an archaeological dig near Dover TN and we explored a dump spot for an iron furnace. It was loaded with slag glass. Mike Gramly wanted some points made from it and I made him several. Some of the pieces were fairly clean and chipped well.

 

[fuss]

Is there a way to tell it's slag and not obsidian just by looking at it, or do location and other factors come into play?

The bubbles are the # 1 identifier.