On Mon, Feb 13, 2017 at 8:27 AM, Ray Sheley Jr. 
wrote:

> have a vernier caliper and averaged out the height, width and length
> dimension, as noted this stone is NOT square and dimensions taper
> .030-.040" everywhere.
> But except for the dish all planes are reasonably straight surfaces so
> average dimensions should suffice.
> I end up with about 22.713 in³ of stone which weighed 2.17# on a kitchen
> scale.
>
> My napkin calculation puts this at a specific gravity between 2.6 and 2.7,
> and it does NOT compensate for the dish which would push it towards the
> higher side.
>
> I'm fairly confident that this has been identified as being a BLACK HARD
> ARKANSAS, and worth some effort to make it serviceable, thanks.
>

Well done good sir.  May use that to work out a few of my questionable one.


-- 
Kirk Eppler