Millefiori (Italian: [milleˈfjoːri]) is a glasswork technique which produces distinctive decorative patterns on glassware. The term millefiori is a combination of the Italian words "mille" (thousand) and "fiori" (flowers). Apsley Pellatt in his book Curiosities of Glass Making was the first to use the term "millefiori", which appeared in the Oxford English Dictionary in 1849. The beads were before then called mosaic beads. While the use of this technique long precedes the term "millefiori", it is now most frequently associated with Venetian glassware.

The manufacture of mosaic beads can be traced to Ancient Roman, Phoenician and Alexandrian times. Canes, probably made in Italy, have been found as far away as 8th century archaeological sites in Ireland, and a piece of millefiori was found, along with unworked garnets, in a purse at the early 7th century Anglo-Saxon burial site at Sutton Hoo.

More: https://en.m.wikipedia.org/wiki/Millefiori