danjared
Well-Known Member
Some months ago, I came upon a coticule of an unusual size. It was described as being exceedingly fast and was large: 250mm by 60mm (about an inch thick) to be exact. It is a natural combo. Because of the supposed freakish speed, the price was pretty low too. Well, I've played with it a bit but only finally came to some strange conclusions about it. It's a rather odd specimen indeed.
First, I noticed that it has two personalities. After a fresh lapping, it is very smooth, resembling a La Veinette in its "soft" feel and appearance, although it is a bit more yellow. But, after, say, 20-30 laps, it starts to become rough. I couldn't figure out why. I noticed that the edge it left was heavily microchipped. There is some vein down the middle, bisecting the hone into two shorter ones. It looks like some quartz-rich region, and I figured that might be causing the microchipping. After some testing, I determined that that's not the cause. In fact, after freshly lapping the stone, I can hone on water for a little bit and not get any microchipping. But, after a bit of time, the microchipping starts! Argh! It took me a while to realize this, but it seems that, after a fresh lapping, it is smooth, but a bit of use seems to quickly release the binder, leaving what is presumably a high concentration of garnets on the surface. The stone visibly changes appearance from a soft, somewhat glittery yellow to a much more glittery and more whitish color. The feel goes from smooth to feeling somewhere in between my Shapton 220 GlassStone and my worn in DMT course hone. In fact, on water, a razor starts leaving a trail of black on the stone faster than on my Shapton 1000 GS. I can only wonder how this stone left the warehouse or saw use. It arrived with a "Made in Belgium" stamp on the side and with some noticeable dishing.
It will likely end up as a stone for knives, where the microchipping does not matter. I just wish I understood its properties better. I'm considering cutting a chunk off one end for analysis. It's plenty long after all.
First, I noticed that it has two personalities. After a fresh lapping, it is very smooth, resembling a La Veinette in its "soft" feel and appearance, although it is a bit more yellow. But, after, say, 20-30 laps, it starts to become rough. I couldn't figure out why. I noticed that the edge it left was heavily microchipped. There is some vein down the middle, bisecting the hone into two shorter ones. It looks like some quartz-rich region, and I figured that might be causing the microchipping. After some testing, I determined that that's not the cause. In fact, after freshly lapping the stone, I can hone on water for a little bit and not get any microchipping. But, after a bit of time, the microchipping starts! Argh! It took me a while to realize this, but it seems that, after a fresh lapping, it is smooth, but a bit of use seems to quickly release the binder, leaving what is presumably a high concentration of garnets on the surface. The stone visibly changes appearance from a soft, somewhat glittery yellow to a much more glittery and more whitish color. The feel goes from smooth to feeling somewhere in between my Shapton 220 GlassStone and my worn in DMT course hone. In fact, on water, a razor starts leaving a trail of black on the stone faster than on my Shapton 1000 GS. I can only wonder how this stone left the warehouse or saw use. It arrived with a "Made in Belgium" stamp on the side and with some noticeable dishing.
It will likely end up as a stone for knives, where the microchipping does not matter. I just wish I understood its properties better. I'm considering cutting a chunk off one end for analysis. It's plenty long after all.