Limestone
A pile of limestone at Conklin Limestone
Company.
A close-up of a piece that weighed several
hundred pounds with about a 20# piece of pure limestone resting on top.
The large piece had some other colors in it. My guess is that this is what
is called marble.
I read that a drop of vinegar on limestone will fizz. I brought home about a 5# chunk to observe this reaction. Might have to carry a small bottle of vinegar with an eyedropper to test stones :o)