Natural Japanese Whetstones, or "Ten-nen Toishi^?," have gained a reputation as being among, if not the, best whetstones in the world for blades of all sorts. In recentyears, they have become particularly sought after by straight razor users all around the world. However, along that that growth in popularity has come confusion and frustration at the variety of names and colors and everything associated with them. 

Reading coticule.be gave me an urge to try one of these apparently unique, rare-ish "Les Latneuses" coticules.

I won't go into details about them, because I don't really know, but the difference about this is that they are a natural combination but instead of a BBW back, the coticule is fused with a greenish stone that seems to have properties very different to the coticule proper.