Thread: Hone info?

This hone belonged to my grandfather. He used it for knives and tools, and used oil on it. When I got it I lapped it, and removed a large amt of material. I posted it on SMF for an ID a while back, I think that I was told that it was a carbonatium (however you spel it) hone, but I don't think thats right. I'm pretty sure that this is a natural stone, and I think I read the carb hones are synthetic.

I originally thought that the darker areas of the hone were just stains from the oil, but when they are held at an angle to the light it looks like mica or something shiny is embedded. I was able to capture a little of this in the pictures, pictures 2 and 4 are the best in this regard. Also the oil would have had to have soaked pretty deep into the hone, as I said I lapped alot of material off the top.

The hone is a little darker then it looks in most pictures, the first and fifth show the colors fairly well. Most of the close ups are a bit washed out.

The "mica" is in the darker areas. The sort of gray greenish areas don't seem to have it, which also makes me think that its a part of the rock. However, I guess the oil could have done something to it to cause it to look that way.

I'm also curious about the "splotches". I originally thought they were another effect of the oil.

The last pic shows the partially lapped back side of the hone. The two really dark areas in the center still have a layer of gunk. The hone was covered with this when I got it. The hone is really hard, and those two holes are pretty deep, so I don't think that side will be lapped flat anytime soon.

It measures 8 inches by 2 inches.

Thanks in advance for any info.

By "carbonatium" I wonder if you mean carborundum? Anyway, I don't think it's a carborundum, at least not one that I have ever seen. The longest rectangular carborundum I have seen is 6 inches. (I do have one that is longer, but it is canoe shaped and since there is currently a cat sitting on my lap I'm not going to bother looking to see what number it is.) The carborundums were synthetic, as you said. I certainly can't tell from your photographs if yours is a natural or a synthetic. Synthetics tend to be homogenous while naturals usually reveal themselves to be so by being heterogenous, though some natural stones, like Eschers, can be remarkably homogenous.

You wrote that your stone is 8x2, but how deep is it? I only ask because it seems that most synthetic hones are fairly shallow while yours looks to be rather thick. That alone makes me wonder if it is perhaps a natural, but I have no idea what it is.

Sounds right on the stone name. All I remember is that it started with "carb" and ended with "m" and sounded like something from star trek. I pretty much made up the letters in the middle up there.

Its not really all that homogeneous, or it doesn't seem to be, I'm operating on the assumption that its unlikely that oil could soak that deeply into the hone and stain it, giving it those darker areas (and the flecks). Plus it just seems like stone. There are probably synthetic hones that seem really close to stone and be able to fool someone, but I think a person can usually tell the difference between an synthetic stone and a natural, unless the synthetic was purposefully made to appear natural.

Its a little over 3/4 inch thick. Its was thicker, but I had to lap both sides pretty aggressively to get to good material. I suppose its possible lapped 1/4 off, since that would have made it about an even inch deep. I went after the still bad side with a powered hand sander.

A couple of things that might help, the mica looking stuff actually is in the lighter areas, theres just not as much of it. Also I tested to see how its hardness compared to a Chinese 12k. The hone was able to scratch the 12k, but the 12k couldn't scratch the hone, which means the hone is harder than the 12k.

I have never tried it, but I have seen threads in which others have described good success with oven cleaner for removing oil. You can also try soaking it in alcohol or kerosene to dissolve the oil, if there is any oil.

I see now what you meant about the mica. That further suggests that it is a natural. I have no clue what it is. You might want to contact a forum member named Howard, proprietor of the Perfect Edge. I believe he's a geologist and has a lot of experience with hones. He's probably your best bet.

Thanks again. I'll definitely take up your advice about Howard (I got my Norton from him). I wanted to contact him about something else, anyway. I didn't know that he actually was a geologist.