Thick stone slab?

Is it possible to get marble or some other suitable stone in a 2.5-3.5" thickness? I have an industrial machining cart that I use as a kitchen island and I would like to add a thick marble top to it. I'm interested in something with unfinished edges. I know almost nothing about this and would appreciate any advice and/or suggestions including types of stone and if and where I could get a thick slab of marble ~ 24 x 36 inches. I live in Boston, MA. Thanks.