Thread: coticule vs escher

Originally Posted by English

I have only used the coticule, but I have had two of them. What I can say is that the first stone cut faster. Don't ask what happened to it, lets just say it broke into many pieces.

When I went to buy a replacement and my jaw dropped when I heard the price, I was told that for a period the Belgian mines had closed down because it had become uneconomic to mine the stone. It's quite recent that new mining equipment together with customer demand had allowed the mines to reopen and the latest stone which is from a deeper sources in the mine is naturally harder and every bit as good if not better than the older stone. He said that when the mines closed, the story went around that they couldn't find good quality stone anymore. He said that just wasn't true , it was purely an economic decision. The mines were making no money. Unfortunately when the mines reopened, the stigma that the new stones were not of such a high quality persisted. He said as a seller and user of the stones for many years and that included both new and old stones, it just wasn't true. He believed that as a general observation, the new stones which are from deeper in the mine are the best quality he has ever seen. He did say that of course with any natural product, some stones are better than others and many years ago, there was a lot more product to choose from.

This might all be rubbish information of course as it comes from one source. but the guy had been selling coticules all his life and should know what he was talking about.

So what's the difference between similar types of natural product? To some extent it must depends on the quality of the stones you are comparing. The differences to me sound so minor that one man's coticule might be better than another man's escher or vice versa. I don't think there is a definitive answer, so the search will have to go on.

I'm afraid this information is not entirely correct.
It's true that there's a big difference between the old mining methods of Coticule and the modern quarrying method. But it's not true that they are mining deeper.
Coticule occurs in small layers that go straight down, take a U-turn at some depth (could be 30 meter, could be more) and runs back up again. To mine it, they used to carve out a ditch, about 1.5 meter wide, 30 meter long and a man's length deep. Only a small part of the harvested rock was usable coticule. When the ditch was fully excavated, they would make holes just above the bottom and place wooden beams in those holes. Then they filled the ditch back up with the original rock, minus the coticule of course (mostly Belgian Blue stone). They left a pit at either end. At that point, they dug deeper and mined another "ditch", UNDERNEATH those wooden beams. When that new shaft was completed, they placed wooden beams at the bottom again, filled it up with the mining debris, and started the next level below. That way, they build their mines, over many years, from the top down. I've included a (bad) picture of an old educational drawing, and some other pictures of the quarry where you can clearly see the holes of the beams, and even some remains of the former mine. Nowadays, at Ardennes, they are quarrying one of the many old mining sites, by basically blasting it out with TNT (one big blast every year) and sorting out all that previously mined and put back material. In the old days, they could not harvest all coticule. Some of it was to hard to handle without the use of diamond cutting tools, some of it could not be dug out, because it would have caused the wooden beams to collapse. All that coticule is quarried and used today. Only with the last detonation, they have reached the lowest level of the ancient mine. They know that, because there's a shaft that's not been filled up. (see attached picture) They have good hopes that the coticule vein continues to run deeper. If so, they're about to enter fresh, previously unmined coticule layers.

Does this all mean they are selling inferior coticule at Ardennes, today? I don't think so. In the pre-synthetic hones era, the speed of a hone was of primordial importance. Grading was primarily done on speed of the hones. Slow coticules no matter how fine, were not considered worthy product. Today, the emphasis on coticule use lies much more on its polishing abilities as a finishing hone. So the old grading system, which rated many different layers (they all had names) with different purposes for various types of hones (razor hones, woodworking hones, cobbler hones, etc...) should be completely reconsidered, because almost nobody sets a bevel on a coticule anymore.

Wow, there are some seriously well educated folks on these forums. I don't have any info that's comparatively valuable, just want to say thanks to everyone in this thread who comes with the smarts!