bead
The Mother of All Bead Furnaces: Testing a Hypothesis about a Natural Draft Bead Furnace
Kicking Ash, Viking Glass Bead Making
Experiment Background
Unfortunately, no intact furnaces survive. Only the base plates for these potential furnaces and an additional scattering of sherds exist in the archaeological record. Thus, the shape of the body, lid, and chimneys must be inferred and then tested through experimental bead production.
Beads
Small and usually round balls made of glass or stone et cetera strung with others for example in a necklace.
Definition source: Chambers 21st Century Dictionary
What kind of jewellery did people wear in the Middle Ages (NL)?
Well, that depended on who you were. There were large differences in classes, between farmers, civilians, clergymen and the nobility.
Often jewellery was about your profession (if you were a man)...