What could this be?:confused:

[AJupstateNY]

Greetings,
This was found while doing a location for a new garden at a house in Upstate NY.
It appears to almost have a seam around it? I guess it may just be one of those
unknowns we all deal with.
Thanks,
AJ

 

[Aarong81]

I did some calculating and figured out that it is too heavy to be Granite, Marble, Travertine, Limestone, Sandstone, Slate Quartzite, Onyx, but then I calculated the deminsions/weight and its nearly an exact match to BASALT.
I calculated a 28.5mm sphere, an average between your two measurements, @ 3.011 g/cc(BASALT) which comes to 36.496g.

So I searched BASALT BALL and it seems to be just that. Some others were excavated along with mortars. Its presumed to be a mortar and ball for grinding corn, flour, ect.

I believe it's fairly conclusive that this is what you have.
SOURCE

http://swvirtualmuseum.nau.edu/gallery3/var/resizes/prehistory_preserved_in_the_national_park_system/southern_colo_plat_parks/Wupatki-National-Monument/artifacts_of_the_past/groundstone-1173926058/Wupatki_20091123_167.jpg

 

[AJupstateNY]

Aarong81,
I think you have it! Sure looks and sounds right.
Thank you,
AJ