Use the color to get an idea of the age. Blue glass Ball jars were produced in the late 1890s and early 1900s, but the company stopped producing these in 1937. There were also some brown amber jars produced in the 1950s, but most of the jars produced after the 1940s were made of clear glass.

Why are vintage Mason jars blue?

Feeling Blue Those blue mason jars were mass produced until 1937 using sand from around Lake Michigan. It was that sand that gave the glass its blue hue.