A birthstone is a gemstone that is associated with each month in the Gregorian Calendar. During the 18th century, the idea of gemstones as birthstones became popular. Owning many gemstones was not something most people could afford. Eventually, it became fashionable to wear only the gemstone of one’s birth month. People liked the idea that wearing one's birthstone brings them good luck and protects them. Today, it is also very popular to wear other gemstones for their color or for their gemstone meanings and healing properties.