Glass facts

Before people learned to make glass, they had found two forms of natural glass. When lightning strikes sand, the heat sometimes fuses the sand into long, slender glass tubes called fulgurites, which are commonly called petrified lightning. The terrific heat of a volcanic eruption also sometimes fuses rocks and sand into a glass called obsidian. In early times, people shaped obsidian into knives, arrowheads, jewelry, and money. We do not know exactly when, where, or how people first learned to make glass. It is generally believed that the first manufactured glass was in the form of a glaze on ceramic vessels, about 3000 B.C. The first glass vessels were produced about 1500 B.C. in Egypt and Mesopotamia. The glass industry was extremely successful for the next 300 years, and then declined. It was revived in Mesopotamia in the 700's B.C. and in Egypt in the 500's B.C. For the next 500 years, Egypt, Syria, and the other countries along the eastern shore of the Mediterranean Sea were glassmaking centers.

Early glassmaking was slow and costly, and it required hard work. Glass blowing and glass pressing were unknown, furnaces were small, the clay pots were of poor quality, and the heat was hardly sufficient for melting. But glassmakers eventually learned how to make colored glass jewelry, cosmetics cases, and tiny jugs and jars. People who could afford them the priests and the ruling classes considered glass objects as valuable as jewels. Soon merchants learned that wines, honey, and oils could be carried and preserved far better in glass than in wood or clay containers.

The blowpipe was invented about 30 B.C., probably along the eastern Mediterranean coast. This invention made glass production easier, faster, and cheaper. As a result, glass became available to the common people for the first time. Glass manufacture became important in all countries under Roman rule. In fact, the first four centuries of the Christian Era may justly be called the First Golden Age of Glass. The glassmakers of this time knew how to make a transparent glass, and they did offhand glass blowing, painting, and gilding (application of gold leaf). They knew how to build up layers of glass of different colors and then cut out designs in high relief. The celebrated Portland vase, which was probably made in Rome about the beginning of the Christian Era, is an excellent example of this art. This vase is considered one of the most valuable glass art objects in the world.