12 Gemstones are inlaid in the Breastplate of High Priest (Aaron was the first High Priest) to represent each of the 12 tribes of Israel. Emerald to represent Levi, peridot to represent Simeon, Sard to represent Reuben, Moonstone to represent Naphtali, Lapis Lazuli to represent Dan, Turquoise to represent Judah, Amethyst to represent Zebulun, Agate to represent Asher, Hyacinth to represent Gad, Jasper to represent benjamin, Carnelian to represent Joseph and Chrysolite to represent Isaachar.
In the book of Revelation, there is a city wall described as having 12 layers, each layer made out of different gemstones. The gemstones mentioned in Revelation are similar to the ones mentioned here, with differences in order. A few stones are also different, possibly due to the translation involved.