Hi Ralphy,
Yes, you probably have one, or three...
I think anyone who has tried to snag a disguised coticule off of the UK ebay has wound up with these. Here are a couple pictures (stone is roughly 8x2):
The color is pretty close to the first picture. This one was absolutely clean (this is originally the underside) and shows coloring which I believe use with oil winds up hiding. It also doesn't have the "burn" marks which are so common. Though the other side does. Perhaps oil erodes inclusions in this stone over time? They have been described as "sandy" and I would agree, especially with slurry.
I don't like my 1k so much so I have been using this one. It works fast, and lightning fast with slurry (DMT card and hard rubbing...). But it leaves a rough edge on a razor, easy enough to smooth out with some good slurry strokes on a coticule, and in my estimation much sharper than a 1k leaves. If I am not doing edge repair, then I use it on water (with soap) just to make sure a bevel is nice and straight, too much, maybe more than 50 x-strokes, will start roughing up the edge.
I have taken a tool steel wood chisel from major chips (2mm) to shaving arm hair above the skin with one of these stones in about two minutes. They are perfect in the shop due to the speed and fineness. I have passed a few of these on to friends for general use. They are far superior than anything we can get in this country.
Though there are blowhards repeating the common "wisdom" that novoculites are all arkansas stones from the US, the prevalence of this stone in the UK, and their rarity in the US, is probability enough for me to think their origin is British.
regards,
Torolf