Purchase Only from Trusted Sources
In recent years, counterfeit natural whetstones have increasingly appeared on auction sites and flea-market apps.
Some are nothing more than ordinary bricks stamped with markings such as “Shohonzan” or “Nakayama.”
Because they are sold at attractive prices, many people mistakenly believe they have found a rare bargain and purchase them on impulse.
However, as mentioned in our earlier articles, it is extremely difficult for the general public to distinguish genuine natural stones from fakes.
For that reason, we strongly recommend visiting a trusted specialist shop in person when purchasing.
When buying online, choose only well-established stores that allow prior consultation.
This minimizes the risk of paying a high price only to receive a stone that is completely different from what you imagined.
The same principle applies not only to natural whetstones but also to hōchō (Japanese knives) and other fine handcrafted tools.
Occasionally, we meet customers who bring in items purchased online to seek advice at a knife shop.
This is somewhat contradictory, as purchasing from a professional means you are also purchasing their knowledge, discernment, and trust.
Naturally, the price reflects that value.
If you still wish to find a lower price, please do so at your own risk.
No Two Stones Are Alike
The most fascinating—and at times challenging—aspect of natural whetstones is that no two are ever the same,
even when mined from the same region and geological layer.
As their name suggests, these are truly natural stones, each with its own personality.
Even stones of similar type may differ subtly in feel and performance.
If synthetic stones can be described as “obedient children,” natural whetstones are more like “spirited and unpredictable ones.”
Because there are no standardized grit numbers or consistent manufacturing methods,
they are difficult products both for sellers and for buyers.
A stone that once felt perfect may suddenly feel different when used on a knife of another steel type,
or hidden layers may reveal themselves over time—each stone truly offers a one-of-a-kind encounter.
Every stone also differs in hardness and polishing power:
some excel at honing the micro-bevel or uraoshi, others at refining the main bevel,
and some at producing a mirror-polished finish.
While some claim that using natural stones from the beginning accelerates one’s sharpening skill,
this is only recommended for those with a deep passion for the art of sharpening—the true enthusiasts.
For most people, the uncertainty of quality and the high cost can make such a purchase daunting.
Those who wish to avoid disappointment should purchase from a shop that allows test sharpening before buying.
Conversely, those who delight in exploring each stone’s unique character will find endless fascination in trying different ones.
Mind the Storage Environment
Natural whetstones are more sensitive to environmental changes than synthetic ones.
Especially in winter, they must be thoroughly dried after use before being stored.
If water remains inside and temperatures drop below freezing, the expanding ice may cause the stone to crack or break.
Even when properly stored, sudden fissures can appear, and in the worst case the stone may split in two.
To help prevent this, one effective method is sealing the sides and base with cashew lacquer.
By coating the non-working surfaces, water absorption is reduced and the stone becomes more resistant to impact.
Given the high value of these stones, it is worth taking the extra care to protect them properly.
Why Natural Whetstones Remain Irreplaceable
Despite the drawbacks mentioned above, the enduring popularity of natural whetstones is easy to understand.
They offer a sharpness and beauty that no synthetic stone can replicate.
The abrasive particles in natural stones are softer and have irregular shapes that are less likely to scratch the metal’s structure.
As a result, they create an edge that is smoother and more refined,
allowing you to cut ingredients cleanly without damaging their cellular structure and thus preserve flavor and texture.
Another great appeal lies in the aesthetic quality of the finished surface.
Because the abrasive particles have a delicate balance of hardness and softness,
they polish the soft jigane and the hard hagane differently,
causing the hamon line to stand out clearly and beautifully.
This is the same principle used in the polishing of honyaki knives and Japanese swords:
the contrast between hard and soft areas of the steel emerges as distinct patterns of grain and temper line.
Such exquisite results can only be achieved through the subtle and controlled polishing power unique to natural whetstones.
Natural whetstones are undeniably demanding and not suited to everyone.
Yet for those who engage sincerely with their tools, investing time and care,
these stones respond with depth and beauty—an embodiment of Japanese craftsmanship and aesthetic sensibility.
Once you experience their charm, a natural whetstone will no longer be just a stone,
but a lifelong companion on your journey of sharpening.