it's signed Vilca
http://www.collevilca.it/en/company/the-collevilca-crystall/origins of the COLLEVILCA crystalworks"In 1947, the brothers Franco and Mario Brogi, esteemed craftsmen from Colle, went to the Waterford factory in Ireland and the Glass Fabrik Sigenuart in Switzerland, where they experimented with different forms of expression in crystal and were able to compare their own experiences with those of these great European companies.
In 1958, after this fruitful journey, they established the Vilca Crystalworks in Colle di Val d’Elsa.
In 2003, Franco’s son, Giampiero, and Mario’s daughters, Laura, Patrizia and Frida, bought the famous COLLE crystal works, merging the two companies under one brand with one production system.
COLLEVILCA is currently the Italian company that holds and transmits the great artisan tradition for crafting crystal, creating its products exclusively in its plant in Colle di Val d’Elsa (Siena, Italy)."