This #25 grade Nakayama colorful-iromono is 208 x 83 x 25mm thick, weighs 922gm (32.25oz) and proves to be a Mohs 4-hardness. The surface from front to back is a wash of yellow dull-orange. One side has a skin, kawa that is brown to black which has a fine kawa pattern that sparkles in the sun. At one end there is a crack as you can see that I filled with marine grade spar varnish. This inclusion is now stable.
 
The sides of the stone were formed with a 2-man push-pull hand saw called tsuru-noko, a saw used to shape the sides of the stone at the mine entrance before they were back-packed down to the village of Umeghata. The back surface of this and all Hoard stones were roughly finished with one man chipping hatchet called a hatsuri.
 
This stone came from The Hoard Collection of Edo to Meiji period mined and finished awasedo that my wife Emiko discovered in a retired hardware store in Kyoto in 2015.
 
There is a stone size & shape grading scale graph on page 87 of my book "Japanese Sharpening Stone Heaven, Narutaki Awasedo"
 
This and all of my stones are shipped double boxed, and include within a tested tomo-nagura slurry stone.