Hi Bernard, many thanks for your reply.
I must admit I had difficulty in deciding the best way to describe the effect. It's certainly seems unlike the cloud glass produced by Davidson, Walther, Reich etc. Maybe I should have described it as "cloudy" rather than "Cloud".
It's also different to the opaque glass I usually associate with malachite in that it is semi-transparent. Having said that, there are parts, especially the base and handles, which do look opaque. Possibly that's due to the thickness or that the colours have been mixed together more by the pressing process?
I'll try to take a photo which better shows the transparency.
Robbo