This unique kitta-nomazu (colorful carp fish scale pattern) awasedo is from the Air Raid Shelter Hoard of stones that my wife discovered in Kyoto. All of the stones I bought from the shop have hand-sawn sides, and the backs were chipped flat with a chisel. This dates them to be pre-1915. This stone was mined most likely in the Meiji Period, according to the seller, who's grandfather began the hardware store which the same family still owns.
The size is 190x68x28mm or 7 1/2 by 2 3/4 by 1 1/8th inches thick.
The hardness is 3.5 (Mohs) or 4 on the common (universal) scale.
 
All of my stones come with a tested tomonagura slurry stone. The are lapped flat, and are carefully double boxed,