Information on that link discussing the item (Museum inventory number from Basel I linked to above in post 29 . It gives a different diameter size to the piece if I have read it correctly (the inventory number is the same 1917.824.)
It says the spherical item is 3.7mm not the 3.25mm given in the museum link I gave above.
Aus dem Katalog: Kat.Nr. 44, S. 124-127
Venedig, 16. Jhdt.
Glas farblos und in verschiedensten opaken
und transparenten Farben. Gold.
Fehlstellen, geklebt, kleine runde Abplatzungen
D 3,7 cm
Basel, Historisches Museum, Inv.1917.824
It appears when translated via google (always difficult to ascertain whether the google translating is correctly done and correctly read by me) to say that these balls were solid.
The PK also gives a written Latin version from Sabellico. When I translate that I find it hard to see where he is describing a ball? It looks like he was describing millefiori canes?