This is truly a work of art! It is an unusual bullicante Murano Venetian hand blown shell shaped vase/bowl. I attribute it to Archimede Seguso as it is his form of work. It is unusual due to the fact that it is 2 heavy 'summerso' water form layers of glass: the interior is of a pale pearl pink " the clam shell and the exterior layer is of a clear, pale bluish green the "sea water" = a sea shell in the sea holding a pearl. This method of blowing glass is called summerso with an ?alabastro interior but it is also rare due to the fact that it was made in the heavy dense thick glass called "bullicante" which was done mostly in the mid-century period. This shell as is often with this design has a pearl. This clamshell of hand blown art glass is of the -Mid-Century Modern period