Goblet

The Poldi Pezzoli Museum has various examples of sixteenth-century goblets in clear crystal glass.
This is not plain colourless glass but a glass of particular purity and transparency, produced by using a better vitrifying material (quartziferous pebbles) and repeated treatments.
Angelo Barovier is credited with developing these complex processes in about 1450. After that date, goblets of great refinement and purity become common, with bowls of different forms and the typical baluster stem, blown separately and then fused while hot to the cup and foot.
The cup in this case is cone-shaped below while the rim opens out into an octagon.