Granite or sandstone

[Older The Better]

Have had this rock sitting on a shelf because I found it buried in a site. When I found it I thought it didn’t look like much but it also was slightly unusual for the geology of the area… I assumed it was sandstone because that’s common in the area but it’s usually platy and angular so I kept it incase it turned out to be something. I picked it up today kind of absent mindedly and noticed the light color where I probably hit it with a shovel. After cleaning it more I’m not sure what it is. A sandstone or a quartzite or a granite.
I’m curious what you guys that actually have hard stone in your area think. If turns out to be an imported stone buried in a na site what it would be for? a nutting stone or a cooking stone or something else? It may be tough from pictures but I’ll give it a shot.

I thought the dark spots were lichen and the reddish bits exposed to heat but I’m wondering if the dark spots are biotite mica and the red k feldspar if I remember my classes right. I really want to knock off a corner but if it is something I’d rather not damage it

 

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[CreekSide]

Looks natural to me. If it displays a different color it would be from heat if it was used. Looks like what I call quartzite which could very well be a sandstone instead. I’m not a geology student. What do you think it was used for?

 

[Older The Better]

That’s the rub, some kind of nutting stone or a weird pestle… I don’t think it looks like anything but found near a bluff top, dark black dirt over a layer of red dirt over rough white limestone, lots of flakes and probably 15-20 tools or fragments mixed in, and a cobble of Sioux quartzite has been found, so even sandstone would be odd but it can be found nearby, but quartzite and granite don’t exist around here so even if natural it was brought in by someone… I know the pics are difficult to tell, I may whack a chunk off of the opinion is it’s nothing but before I damage it I thought it was worth an ask

Here is a picture of a piece of rock from like 300’ under New York that I got this year. Seems like a similar stone where it’s scratched like a heavily patinated granite… thought about soaking it too but I’d rather not alter it if it is something

 

[Older The Better]

I’m not trying to prove anything just mulling it over but maybe something like this?

I don’t know if it’s obvious but it’s a bit cup shaped on that top face and a little on the opposite

 

[CreekSide]

It’s not a cubic nutting stone I have one in my collection I’ve found. If you feel strongly for it. It could be an anvil stone for use like a lap stone for point making. Most are just heavy dense flat stones.

 

[Older The Better]

I’m getting closer to knocking off a hunk or touching it to a grinder I’ll let it simmer for a while longer though, appreciate the thoughts I know it’s not super exciting but when it feels like -10 outside I’ve been inside all day.

 

[CreekSide]

I’m getting closer to knocking off a hunk or touching it to a grinder I’ll let it simmer for a while longer though, appreciate the thoughts I know it’s not super exciting but when it feels like -10 outside I’ve been inside all day.

Todd would know better than myself as to the proper name of it. He is a knapper which I am not so I don’t know the proper name. It could be a metate if it shows a grinding dimple in the center.
It’s cold here too so I know how you feel. They said snow for us Monday but have changed it which I’m glad. But next week it’s going to be in the teens a few days. Stay warm

 

[ToddsPoint]

I would say by your pic that it is diabase, which is an intrusive igneous rock. Same minerals as basalt but cooled differently. Formed in a volcano but cooled relatively quickly which gives it the fine grain. In central IL that was the preferred rock for making celts and axes. Our supply of diabase came from Canada via the WI glacier.

 

[dognose]

I don't think it's a nutting stone. It does not have the features I would expect to see.
To me, it appears to be a naturally occurring stone.

On the other hand, it's possible it may have been used, at some point, as an abrading tool. When knapping the rough edges of a blank are smoothed. Or if used for manufacturing a hardstone tool, it could have been used in the grinding a celt or axe.

In a few photos it looks like peck marks but magnify an image enough you will start to see dimple like features that are not necessary peck marks.

Bottom line, for me, I can't tell unless I see it in person and even then, I may not be able to determine one way or the other.
its worth keeping.

 

[Treasure_Hunter]

Nothing I see in pictures says anything other than natural stone.

 

[Older The Better]

This morning I did some more destructive investigations… turns out that peppery diorite color was an anomaly. First I tried a power sanding, and then a wire wheel on a bench grinder. This is the result

What I did notice was it was throwing a few sparks while on the wire wheel… so I flipped sides and used a stone wheel it was surprisingly hard after a fair amount of time on the wheel this as far as I got

That proved it wasn’t diorite like the scratches suggested but being so hard it wasn’t the usual sandstone so I knocked a corner off and I think I got my answer

I think it’s an orthoquartzite or silicified sediment/ quartzite so I looked into that and found this which I think is a reasonable id

So, what I’m seeing right now is a stone imported from the north, which would fit with the Sioux quartzite piece I found in the same place, that wound up in buried context in a na site 150 miles south or more. It may be natural but it isn’t from this area. Why it’s here isn’t clear but I suspect it had some purpose maybe like an abraider mentioned above, but with no definitive marks of alteration by man It is what it is, a curious stone out of context. I say at the least it shows a connection between people in this area and those in northern Kansas and Nebraska wether through trade or movement. Appreciate all those that looked and provided insight.

 

[ToddsPoint]

It does have the look of quartzite now that you got into it.