Thank you for that information Richard which proved to be
most interesting. I made an internet search for mammilated
chalcedony and now recognise that I have seen this type of formation; I have to
admit not in the field, but usually in fossil shops or a museum, and I thought
I had found a Cambrian cappuccino! Thank you for posting, this information has
increased my, limited knowledge of the subject, Rock E.
Well I¢¢â¬¢â¢ll be a monkeys uncle, or should that be nephew.