Thanks so much for your reply Sach. I've looked again at signature through a magnifying glass as I too could possibly see 'Mexico'
. It also 'sparkles' as it looks as if the same material in the base of the paperweight has been used and the maker probably european? due to etched signature as capital F is crossed and erro is joined up as is the word 'Murano'. Would love to solve this if anyone can help and find out more about this unusual paperweight as it looks quite old and surface of black base has become quite scratched.