Hi all
    I bought a old oilstone at a car boot sale at the weekend. It only
cost me a quid - I was mainly after it for the wooden (cedar?) case it
came in. Upon examining it more closely I reckon the stone itself is of
pretty good quality. I've been soaking it in strong detergent solution
as mentioned in this forum, since I also have some waterstones and
would likely use it with water/detergent instead of oil. It's starting
to show its 'true' colour, a light sandy brown which (to me) looks not
unlike the colour of the 'Norton India' stones I was trying to avoid
spending 20+ quid on... ;-)

So anyway, partly because I may have got a real bargain, and partly
because ... I'm just interested ... can anyone point me to information
on how to identify the type of stone this is likely to be?

BTW it is one grade only (not a combination stone) and at a very quick
guess I'd estimate it to be around 400 grade

    Cheers
    Jon N