Not quite true, John, you've seen my pale amethyst one.

Christine has mine right now, so I can't count the lobes. It is marked.
However, as we're discussing these, there was a lot of disagreement about how mine was constructed (there was a large group of us, in B'ham, at lunch time).
Most folk think mine is cased. At first loooking one might assume that, but I am of the very firm opinion that it is not - that all the different shades of colour which appear are due entirely to different thicknesses of the glass - it is all one colour.
Does anybody know for sure? (I'm sure, just nobody else was!)