The Hoard Story
The Nakayama, Okudo, Narutaki, Shinden, and other Honyama mined stones came to me from a neglected and nearly forgotten Hoard of stones down in an Air Raid Shelter tucked under the floorboards of an old fashion hardware store. Over the past few years the owner has released a limited group of stones to me from his store nestled in a small rural town in Japan.
With my first opportunity to buy any of these stones, I had to be selective because the because the owner had placed "collectible" prices on them which was much higher than I had ever paid from a professional stone seller. Everytime I went back to the Hoard it seemed that the prices crept a bit higher. But as it turned out, each and every stone was hand hewn, the sides were hand sawn and hand scraped and many of the stones have kawa mineral skin on 3 or 4 sides and this was unique enough to justify the prices. He indicated that they were dated to as early as the late Edo Period and certainly many if not all were mined before the Meiji and Taishio periods. A fact that he had picked up on from a friend.
Some of the smaller stones I could tell were harvested from narrow nooks and cavities within the mine complex. The larger rectangular stones prepared for sharpening knives and tools were large to extra large with the giant of them all, an asagi being 245 x 104 x 58mm thick and weighing 3627grams equaling 7.99 pounds. Many of the stones are over 50mm thick and a few 60mm thick. These are Professional sizes or multi-generational size stones that will last years and years in a shop.
The seller, who was 71 years old when I first met him, told me that his grandfather bought the stones at least 90 years ago and that because the family never had been a stone or tool store, he said that they just never really sold enough to bother with over the years by putting them out on the shelves of his shop.
The use of hand saws to shape tennen toishi sharpening stones from the Kyoto mines dates back to the beginnings and only ceased in the late 1800, so the 1920's most if not all of the mines began to use circular saws. Historic wood block prints from the Kamakura period illustrate crews shaping the stones with hatchet work on the bottom's while 2 man teams sawing the sides with Kibiki.
As a group, but really from stone to stone, this collection is made up of the fastest cutting stones I have ever owned or tested. The fastest of them will remove and replace King 1k or Shapton 2k scratches within 15 strokes or fewer if a slurry is made from the base using a #1200 diamond plate. Without slurry and just clear water the stone will these stone will finish up a Henckels razor to the keenest states with a bright finish with just a little effort.
I have found that each stone is so similar in hardness (slightly softer than modern stones), and cutting speed and fineness, that as a group they all really do represent an era.
The first four photos below show the interior of the shelter, about 5 x 6 x 5ft high. The last photo shows a selection in my shop ready for lapping and polishing.

