How did the idea of birthstones come about?
The tradition of assigning gemstones to the months of the year evolved from ancient astrologers who worshiped the planets and believed they controlled the fate of people. They related certain gemstones to the twelve signs of the Zodiac, as well as the twelve months of the year and the twelve parts of the human body. The idea was to change gems each month, working through all twelve in order to receive all the mystical and therapeutic powers of each of the stones during their optimum time of strength.
Early Jews and Christians adapted this belief during Biblical times. The Book of Exodus contains instructions for the High Priest’s vestments, including the Breastplate of Judgment which is set with twelve gems, each inscribed with the name of one of the Twelve Tribes of Israel. The New Testament of Revelation lists the Foundation stones of New Jerusalem, each of which represents one of the twelve apostles and can be traced to a Breastplate stone.
Gradually, the emphasis became less religious and changed to the wearing one stone, representing the birth month. While the list has changed several times, the current list is as follows:
| Month | Birthstone |
| January | Garnet |
| February | Amethyst |
| March | Aquamarine |
| April | Diamond |
| May | Emerald |
| June | Pearl, Alexandrite |
| July | Ruby |
| August | Peridot |
| September | Sapphire |
| October | Opal, Pink Tourmaline |
| November | Citrine |
| December | Blue Topaz |
