Birthstones are gemstones associated with the month of one's birth. The concept of birthstones has its roots in the Breastplate of Aaron, a ceremonial religious garment described in the Bible. The breastplate was said to contain 12 different gemstones, each representing one of the 12 tribes of Israel.

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The modern list of birthstones emerged in the early 1900s. In 1912, the National Association of Jewelers (now called Jewelers of America) met in Kansas and officially adopted a list of birthstones for each month. This standardized list has evolved over time, but the core 12 stones have remained the same.