View Full Version : Grindstone, what is it?

11-11-2008, 04:34 PM
I purchased a mini-grindstone, about 4 inches in diameter, from Grindstone City, Michigan this past summer. The stone is an even blue-gray color with a fine, even texture. I would estimate it is 400 grit.

Does anyone know what stone this might be? Some type of sandstone perhaps?

Grindstone City is located in the northern most part of the thumb of Michigan. Historically this town made stones for grinding corn, as well as round sharpening stones which were foot powered.

11-17-2008, 07:47 PM
Call them and ask them what kind of stone it is. Don't be surprised when they tell you it's made of "Grindstone"

"Grindstone" is a special rock formation from the Marshall Sandstone. It is a grit stone finer than sandstone and used exclusively as a sharpening stone, which produces a finer edge than carborundum which has replaced it. There were two grades of this stone, one called light because it was nearer the top of the ground and softer. The second grade was called heavy stone and was found several feet under the ground. Besides being heavier it was finer, thought to be due to the pressure from the upper layers.


11-17-2008, 08:19 PM
Hardly a day goes by I don't learn something on this forum. Thanks Klkak.

11-18-2008, 05:03 AM
My pleasure Rick.

11-18-2008, 09:16 AM
Hmm, it's Marshall sandstone. Very fine and even texture. Thanks klkak.

11-19-2008, 01:29 AM
It is amazing what you can find out in 30 seconds with google! Again it was my pleasure.