Most gem scholars believe that birthstone traditions originated with the Breastplate of Aaron. This was a religious ceremonial garment set with twelve gemstones that represented each of the twelve tribes of Israel. The stones also corresponded with the twelve signs of the zodiac.
Note: Translation of ancient biblical descriptions of the stones used in the Breastplate of Aaron into their contemporary names varies dependent on the translation which is cited.
Instructions for fabricating the Breastplate of the High Priest, or the Breastplate of Aaron, can be found in Exodus 28, 15-30.