Identifying Beach Pebbles for Carving?

[Stephen Beat <S.Beat@xxxxxxxxxxxxxx>]

I am a complete beginner to carving stone ... And my
interest is in smallscale projects. In particular I want
to carve sea-shore pebbles from my local - North
Yorkshire (Whitby/Scarborough).

My greatest (...and first...) problem is identifying
pebbles that are good for carving. Hit and miss
experimentation has taught me what is 'hard' & 'soft' -
but I want to be a bit more scientific in my choice of
medium now.

Does anyone know of a good book that might help me in my
identification of sea shore pebbles and rocks?

Otherwise has anyone else chosen this path of carving or
engraving beach pebbles? (I would be keen to swop
experiences).

I realise the majority of you will prefer 'specialist'
stones for your carving - rather than naturally
harvested stone (and I am myself looking into aquiring
some soapstone to experiment with) - but for the type of
subject matter I have in mind beach stone is ideal.

Any comments, advice, suggestions would be very
gratefully recieved.

thank you in advance...

Steve (Beaty) Beat