“Calcedonia" is one of the oldest and rarest types of glass. Calcedonia was first developed on Murano during the mid-fifteenth century. For 500 years, the mystery of creating Calcedonia has fascinated the world. Artifacts made of Calcedonia glass are among the most treasured holdings of many famous museums. The uncertainties and difficulties of Calcedonia glass production were resolved only by the masters of Murano and lost with the fall of the Venetian Republic. The secret of the production of Calcedonia was finally rediscovered by Lorenza Radi in 1856, but lost again by the turn of the 20th century. In 1977, the master Loredano Rosin, working with his brother Dino Rosin, again achieved the miracle of Calcedonia, and used the ancient and historical glass to create hand made sculpture of modern and romantic design. The Striations of color are achieved by adding  silver nitrate to each batch of Calcedonia glass. The exact shades and degree of striation can not be controlled and creates the unpredictable beauty of each piece.