When glass breaks, the cracks move faster than 3,000 mph!

The most typical type of glass is made with 75% silica and is called soda-lime glass. When broken, the cracks on the glass move faster than 3,000 miles per hour. A camera would have to shoot at a millionth of a second to catch it. 

The art of glass making has become popular. Museums and private buyers pay hundreds and thousands of dollars on glass art. Modern glass art includes vases, paperweights, ornaments, and wine holders. Glassmaking can be traced back to ancient Mesopotamia. Glass has come a long way since then, though. 

Today we have different types of glass, too. For instance, polymer glasses are used for eyewear and bottles for its lighter application. Silica glasses are used more for windows. Silica glass is created when lightning hits sand and forms hollow, branching structures called fulgurite. Silica is also known as quartz sand and it is used in most commercial glass production. 

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