Historical records show glass was discovered in 3500 B.C. It featured prominently in Egypt and Assyria. This type of glass was mad-made, differing from naturally formed glass such as obsidian.

Nature’s Glass

If you know anything about the rock cycle, then you’re probably familiar with obsidian. But, did you know it is classified as a naturally occurring glass that forms from lava? When lava cools outside of a volcano, it forms obsidian, a dark black or green glass. It can be cut to have sharp edges, which made it an ideal material for weapons and tools. Due to its composition, obsidian is not a rock, mineral, or crystal.

How Humans Made Ancient Glass

In ancient Mesopotamia, a glass called faience was made using sand quartz and plant ash. Each material would be crushed into fine powders and heated until it became molten. Glassworkers cooled the faience, crushed it, and added pigment before reheating it in a mold at a higher temperature than before. The faience would once again become molten and fill the shape of the mold. After cooling, the mold would be broken away from the glass, leaving the finished product behind.

Use of Ancient Glass

Glass jewelry dates back 3,000 years, with beads being the most popular finished product documented. The Romans and Egyptians used faience glass to produce beads, and eventually the use of glass in jewelry evolved centuries later to include watch coverings.

Glass vessels (vases, glasses, pitchers) were one of the first practical uses of ancient glassblowing. These pieces of art would be painted or etched to showcase designs by the artist. Glassblowing grew in popularity throughout the Middle Ages, and stained glass techniques were introduced.

Glassblowing

Glassblowing is the art of forming molten glass by blowing air through a metal pipe. It dates back to the 1st century. Rotating the pipe, adjusting the amount of air used, and manipulating the molten glass with tools helped produce different shapes when the glass cooled.

Stained Glass

As glass workers hones their skills, they developed windows made of colored glass. Stained glass windows were most commonly used in churches and government buildings, and they often depicted scripture references.

The glass for these windows was traditionally colored using metallic salts, with different pieces being used similarly to a mosaic, coming together to form a bigger picture. The different glass pieces are fused together with lead pieces to create the entirety of the window.

Stained glass windows can also be painted before being fired in a kiln, or a silver nitrate stain could be applied to color the glass before firing. Thanks to the heat of the kiln, these applications can penetrate the glass enough that they are almost 100% permanent.

Modern Glass Making

Glass can also be made from heating sand, soda ash, and limestone. Once this mixture is molten, it can be formed using a blowpipe, molds, and tools. Today, we can even recycle existing glass and use it to make something new. Additives such as iron, boron oxide, and lead can change the appearance and strength of glass, giving it different colors and heat-proofing properties.

The History of Glass in America

While these forms of glass art and their use in structures date back centuries, more modern applications of glass in art and architecture are attributed to the invention of plate glass in the 13th century. Known as broad sheet back then, it was introduced in Sussex, England. Glass production in America wouldn’t occur until settlers reached the east coast in the 1600s, and plate glass wouldn’t be used until the late 1830s for shop windows and public buildings.

Although colonists in the 1600s were capable of producing their own glass, resources were limited and they ended up importing most of the glass they needed from England. It wasn’t until 1739 that a glass company, owned and operated by Caspar Wistar, found success in New Jersey. At this time, glass was still expensive, so few people had glass bottles, art, or tableware. 

Middle-class households in the 1800s had more access to glass products once the pressing method was invented. This process involved the use of molds to form the glass, and it was less costly to produce than hand-cut glass. Streamlining production made glass less time-consuming to create, and the savings were passed on to the colonists.

Throughout the 1800s, glass in America was used to create candlestick holders, lamps, glassware, bottles, and various art. It was also used to make lightbulbs in the late 1800s thanks to Thomas Edison’s findings on electricity. Also during this glass was only used in small sheets for architectural purposes; which is why stained glass windows were comprised of multiple small panels soldered together with lead. Also, since glass lacked strength at this time, diamond-paned windows were common in homes.

Glass in the 1900s

Sheet glass machines were developed in 1902 by Irving W. Colburn, and in 1904 Michael Owens patented a glass bottle maker. Industrial machines made mass production possible and continued to make glass items more affordable for consumers. Also, this glass was stronger and made it possible for windows to feature larger panes of glass.

Glass as a medium for art gained in popularity in the 1900s as well. Yes, glass had been used to make ornate sculptures, intricate jewelry, and other decorative items before, but now it was more accessible to artists. Instead of having to work in factories that produced glass, artists could work with their own small furnaces to heat their materials and form glass.

By the 1960s, cameo glass had another moment in the spotlight. Originating in ancient Rome, artists of the ‘60s began once again incorporating etched layers of glass in their work. Due to widespread interest in studio glass art (versus factory-made, mass-produced glass), universities began offering programs of study related to glass.

As we have put glass to the test over the years, it has gone from a luxury for the rich to something accessible to all. Our homes have glass windows, glass shower enclosures, and even glass as purely decorative elements. Since glass is 100% recyclable, it has become one of the most environmentally friendly building materials.

Famous Buildings Made with Glass

Glass has come a long way since obsidian was hewn into tools and weaponry. Today we have beautiful, iconic buildings around the world that were made with glass.

• Christ Cathedral/Crystal Cathedral – Garden Grove, California, completed in 1980
• Louvre Pyramid – 75001 Paris, France, completed in 1988
• Jardim Botânico de Curitiba (The Botanical Gardenof Curitiba) – Curitiba, Brazil, completed in 1991
• The Gherkin – 30 St Mary Axe, London, England, completed in 2003
• Basque Health Department – Bilbao, Spain, completed in 2004
• The Giant Egg – National Center for Performing Arts, Beijing, China, completed in 2007
• Aldar Headquarters – Abu Dhabi, United Arab Emirates, completed in 2010
• Philharmonic Hall – Szczecin, Poland, completed in 2014

The next time you pick up your cell phone, roll down the window in your car, or sit back to watch a show after a long day, be grateful for the advancements made with glass throughout the centuries.