This is a really interesting and mysterious beast.

First thoughts were that it is very like (but absolutely isn't) Dartington Studio "Alchemy", then my guts veer to WMF, which I don't think it is either.
It is certainly something of serious quality.

I do know of a Bohemian Tye shape Hyacinth, which was opalescent pale blue, (as is the internal pale blue in this) and it was also Uranium.
Does the internal layer react to ultra violet light? Is it Uranium as well as opalescent?
It would be such an unusual combination of things to find, they may be related?
http://lustrousstone.co.uk/cpg/displayimage.php?pid=2767