Need your help honemasters!

Honemasters I need your help! Nobody seems to be able to identify this natural hard stone. Picked it up at the antiques covered in toolbox gunk. Cleaned up & lapped. It's unbelievably smooth and hard. Appears to have been a cream or lighter color originally. I've searched and tried other forums, but their stumped :thinking: Do you know??? Thanks in advance for ur help. :bow

http://img.photobucket.com/albums/v4...nownstone7.jpg

http://img.photobucket.com/albums/v4...nownstone8.jpg

if you like to know can you use this to sharpen straight razor Answer to that question is NO.too course for straight.
if you want to know name of it and etc information Sorry don't now.
I have one and that is why i know how will it act.take care