Nakayama is the most famous of the mines in part because; of the ancient history surrounding the mine, the previous owners marketing skills, and the extremely fine quality of the stones from that mine.
Kato-san who owned the mine from the 1920s into the late 1960s stamped many of his stones with his own personal ink stamp while most of the other miners simply wholesaled in bulk their stones with no mine markings or ink stamps to consolidators who marketed them with ink stamps registered to the wholesaler without regard to mine they originally came from.
Kato-san was particular about the quality in the stones that he chose to slab up and finish with his stamps, he did not as a rule release inferior grade stones and so in this way his mines reputation was built on firm footing, not just on myth.
The location of the Nakayama mine was (it was closed in 1967) on the side eastern side of Mt. Atago, the highest peak in the region was very near to Kyoto. The strata of this area was particularly fine and the stones are known for their even grain and cutting strength and these are the ingredients most important to a finishing stone. Not to say that all Nakayama stones are fine and even, but the majority of authentic older stones you will find have a special luxuriant feel and advanced cutting abilities. Admittedly they are expensive and not for casual users. The majoirity I have sold have gone to sharpening savants, collectors or professional furniture makers or builders.
Currently we need to beware that many of the stones sold on e-bay as Nakayama may not actually be so. The true Nakayama toishi that Kato-san marketed with his own brand in unused condition may posses one or more of these stamps, these stamps will wear off immediately if the stone is used.
If they do not have any of those stamps then you have to look and work with the seller with a careful and clear mind in order to arrive at a conclusion that takes in other considerations. Stones that are vaguely marked Yamashiro or Honyama are not authenticated by Kato-san as Nakayama stones or by the current owner of the Nakayama mine Hatanaka-san. It must be noted that Kato-san did part out wholesale lots of vast amounts of raw stone to the consolidators in Kyoto who may in turn have finished up the stones and marked them with their own copyrighted stamps which may contain the words Yamashiro or Honyama. So there are Nakayama stones with various ink stamps or no ink stamps at all.
Of course over the past 800 years or so the vast bulk of stone from the Nakayama mine did not have ink stamps, the ink stamps are of the 20th century, so there are un-marked Nakayama stones in Japan, just like there are un-marked Nakayama stones here in the U.S.. There are those stones that have been used so that the ink stamps have been worn off plus the stones that were purchased from the Nakayama mine as raw stock by wholesalers or other miners or earlier stones that never did have ink stamps. There must also be in the holdings of the Japanese Imperial household and in other private collections ancient of documented and remarkable examples. The gentleman So Yamashita who owns Japan_Tools.com has suggested in the past that his father can accurately differentiate stones from particular mines by careful inspection. I believe what he claims is true, and it must take years of looking at volumes of stones and talking with miners to be able to do this with percision. I myself have been fortunate to have had some instruction in this area and have begun to realize that with a collection of known reference samples for comparrison, some deductions or presumption may be concluded.
Currently the only actual new to the market Nakayama stones are released by Hatanaka-san, the current owner of the Nakayama mine. He alone owns and has legal use of the name Nakayama Mine along with the copyrighted names and ink stamps associated with it even though the mine is physically closed. He has retained the right to ink stamp any and all of the leftover inventory from generations past of his family business and I am led to believe that many his new releases are slabbed up from huge storage lockers of raw stone that was mined from the time when his father was a partner with Kato-san along with the left over stone from Kato-san’s lockers. Two of the above links are to Hatanaka-san’s stone boutique another is to the ProShop, the chosen main retail outlet for Nakayama toishi in Japan and the last if from my site where I have documented stones from the Kato-san era. Hatanaka-san is managing the business just as shrewdly as Kato by not flooding the market with their stones which move from him through selected channels. He is also monitoring the activities of ink stamp forgers. His company is at the top of the pyramid in the tennen toishi world and his family name is paramont to him. Regarding his heirs, there are no compromises.
You will find from retailers that any full (Size #30 minumum 205mm x 75mm x 24mm thick) size decent and documented Nakayama stone for plane blades will be $600 and up, and that any really fine stone is $2000 and up. Any really great stone (if you can find one on the open market) will be in the $25,000 and up range. This ultra-grade or super quality stone is normally retained by Hatakana-san for retail to his personal clients. I have myself have seen in his shop stones in the $75,000 price range. I also have a suspicion that even if I did have the money to purchase such a stone I suspect that he would first put me through a vetting process.
Be aware that any full size Nakayama stones that are selling for $39.95 to $149.50 on E-bay including free shipping are likely only worth just about that value. And if they happen to be genuine but new to the marked and from the Nakayama mine they were possibly obtained by means outside the normal channels, as in picked up during a casual stroll in the woods near the old mine site.
There is only one Nakayama mine and from it came all of the Nakayama stones. There is no substitute. An example would be that you expect to recieve a Napa wine from Napa Valley if labeled so, and a Sonoma Valley wine from Sonoma if labeled so. There is a common mountain, Mt. Veeder, inbetween the two appellations that defines both valleys and acts as a boarder and they meet at the top, but the wines are certified and labeled as from one of the valleys or the other. The fact being that the last tunnel of the Nakayama mine was closed and was bulldozed and sealed by Ishihara-san, the owner of the Ohira mine in the late 1960′s. Now I understand that there is another mine that approaches the Nakayama mine from another direction, from the other side of the mountain. These stones from this different mine may be of some good quality but they will never be recognized as actual Nakayama stones.
This has been a short overview of the Nakayama mine and its owners. Alx