I agree with the above posts and to add my 2 cents..... if the stones are made up of the OO (Olive-Oil) and ES mixture then surely they should all be the same in texture and consistency. They are then supposedly being formed at the same time, under the same conditions with the same ingredients. My last flush of 2 days ago yielded lots of small bright green stones, large and less waxy brown stones, hundreds of small white very hard irregular shaped stones and about 1 inch wide brown stones that had an egg shell like exterior and were hollow inside. I personally don't think that there are any conditions under which OO (Olive-Oil) could produce that lot. So my thought on Dr. Weil, I won't take anything he says seriously.