Biot glass empty pocket, vintage

Imposing empty pocket in blown glass from biot, vintage. The object is heavy, weighing 1, 700 kg. The diameters of this pocket tray are 17.7 cm at the base and 20.3 cm at the neck. The height of this object is 7.4 cm. Note the barely visible presence of a black dot that I was unable to remove by cleaning it, a priori, it seems embedded in the mass of glass. This does not call into question the timeless beauty of this object.