This abosulutely gorgeous piece of glass is called a Danish Pear.
It's a wonderful blue color.
These floats are classified as OR #238 in Olaf Raabe's book on Euro floats.
This float measures about 7 1/2 inches wide and 9 1/2 inches tall. It's very heavy for its size.
It has excellent provenance having been found by David Neff in Scandinavia.