just recieved this Koma nagura today are these small brown spots inclusions in it?
inclusions ?
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No idea but it looks like a big block of nougat! 
I have drilled mine out. I used my drill press with 1/16 bit and hold the nagura in my hand and move it around the bit.
This is stamped koma but no asano stamp.
I wonder how much of a koma it is? Kind of like Escher with no label thing.
Koma are extrinct, the stock is depleted and right now are extremely hard to find.
I wonder how much of a koma it is? Kind of like Escher with no label thing.
Koma are extrinct, the stock is depleted and right now are extremely hard to find.
That is a Mikawa Shiro Koma, most likely from Takeshi. Some Mikawa nagura are similar to Asano while others are very different and create slurry of a pasty consistency which I happen to like. The spots can be just sediment as is the case on a Mikawa Shiro Botan Gamma and I have or it could be sand. Drill into a spot as Doc said and see what's what. Most of the Mikawa Shiro nagura I've seen and personally used has been very good. Comparing them to Asano is an exercise in futility, they are in most cases markedly different.
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it was sold as a Mikawa Shiro Nagura Koma. There is a 2/3 of the stone that appears clear.
thanks guys i will try drilling them out.
thanks guys i will try drilling them out.
No sense in drilling it out unless it's toxic. Spots like that can be from water seeping through, or any number of other things - mineral deposits, etc. Of course, there could also be a toxic issue - anything is possible, but a spot doesn't mean toxic. I have an old Koma that looks like its impregnated with dirt - aside from being ugly-ish it's actually quite healthy and very nice to use.
Personally - I would test that before drilling. the spots may add something good to the equation. Or not - only way to know is to test it.
Personally - I would test that before drilling. the spots may add something good to the equation. Or not - only way to know is to test it.
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- #8
just had a play with it.
made a slurry from the clear part, no problem.
washed stone and then scrapped some of the small spot onto my stone, seemed to break down.
picked some of what looks like gray grit from inside the large spot, very gritty and would not breakdown.
a coulpe of the small spots also had a grit like centre, these I cleaned out.
next I raised a slurry from the side with spots. This seemed to be ok. more play time is needed to be sure but first impresion is no negitive effects to the feel of honing.
There is approx 2/3 clear nagaura so no real drama. here she is after a light clean up.
made a slurry from the clear part, no problem.
washed stone and then scrapped some of the small spot onto my stone, seemed to break down.
picked some of what looks like gray grit from inside the large spot, very gritty and would not breakdown.
a coulpe of the small spots also had a grit like centre, these I cleaned out.
next I raised a slurry from the side with spots. This seemed to be ok. more play time is needed to be sure but first impresion is no negitive effects to the feel of honing.
There is approx 2/3 clear nagaura so no real drama. here she is after a light clean up.
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- #9
yes they are getting hard to find.
I got this e-mail when I asked Masanori Teshiba if he had any Koma.
This stone is not from him.
"Koma seems not to arrive for several months. I am not so good at English. It is difficult to explain the reason to you. Nagura has already finished digging up the mountain for about 30 years ago. The stone at that time is put on the warehouse in the pile. The big one and a high quality thing were previously sold. It sells it little by little while having piled up a remaining stone like the mountain now. There is no Koma in particular.However, Koma is found from among the stone piled up like the mountain sometimes. It arrives to me that time. Therefore, I do not understand when the stone arrives."
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I just love when my hones are "piled up like the mountain sometimes"
