Crystal Clear

The artisans at the ColleVilca glass-making factory operated like clockwork as they transformed shapeless lumps of superheated glass into beautiful pieces of crystal art. Despite the heavy heat coming from the 1400°C furnace, we continued to watch them work. While the “levapareson”, a helper to the master craftsman, went to retrieve another knob of glowing, molten glass with his metal rod, the “soffiapareson”, or master craftsman, would be shaping his current piece with various tools. All this was done while the soffiapareson continuously rotated the metal rod to prevent malformation and ensured that the glass didn’t get too cool to work with. We watched as the body of a dove slowly grew wings and a beak. Some of us even got to blow our own pieces of glass, which they got to keep. Later, we explored the ColleVilca’s gallery of finished pieces, which included birds, horses, elephants, swords, cups, vases, and more. It was really easy to see how difficult mastering this trade was. It clearly required years and years of practice to develop the patience, artistic skills, strength, and coordination necessary to create such masterpieces.

Before the artisans began molding their glass, they had to gather the raw materials. Glass is made by heating a number of many different components at 1400°C into a vitreous (glasslike) state. Vitrifiers are the main components of glass and they include silica, boric oxide, or phosphoric oxide. Next, fluxing agents such as sodium oxide and potassium oxide are added. Fluxing agents are necessary because pure amounts of vitrifiers would have too high of a melting point. By mixing them together, the glass’ melting point lowers (same as freezing point depression), thus making it easier to maintain the molten state of the glass. The glass can also be colored by adding various metal compounds such as cadmium for red, cobalt for blue, or copper oxide for green.

ColleVilca brand is famous for the crystal that they make, which is one of the best in the world due to its high brilliance and transparency. But what exactly differentiates this special crystal from regular glass? The answer lies foremost with its chemical composition. The main difference is stabilizing agents. Missing in regular glass, these agents have a number of uses. They make the glass look better and easier to mold as well as provide greater atmospheric protection. There are a number of these stabilizing agents – ColleVilca mixes in a minimum of 24% lead oxide. This lead, as well as the invaluable skilled labor, is what gives crystal glassware its quality. 

I never knew that glassmaking could be so intense. It is truly an art that requires a lifetime of devotion to master, but we could see in the faces of the ColleVilca artisans that it is a rewarding trade. 

Works Consulted:

http://www.collevilca.it/en/unionofcrystal

http://en.wikipedia.org/wiki/Lead_glass