While it's said that a birthstone holds the strongest power for the person born in its month, anyone can wear the stones and benefit from their beauty and healing energies.Western Customary birthstones: The origin of birthstones is believed to date back to the breastplate of Aaron which contained twelve gemstones representing the twelve tribes of Israel. The idea of birthstones has a place in many traditions, customs, and belief systems. The first century Jewish historian Josephus believed there was a connection between the twelve stones in Aaron's breastplate (signifying the tribes of Israel, as described in the Book of Exodus), the twelve months of the year, and the twelve signs of the zodiac. Translations and interpretations of the passage in Exodus regarding the breastplate have varied widely, with Josephus himself giving two different lists for the twelve stones. George Frederick Kunz argues that Josephus saw the breastplate of the Second Temple, not the one described in Exodus. St. Jerome, referencing Josephus, said the Foundation Stones of the New Jerusalem (Revelation 21:19–20) would be appropriate for Christians to use.
Traditional Birthstones: Ancient traditional birthstones are society-based birthstones, often reflecting Polish tradition. There are poems which match each month of the Gregorian calendar with a birthstone. These are traditional stones of English-speaking societies. Tiffany & Co. published these poems "of unknown author" for the first time in a pamphlet in 1870.
Official/ Modern birthstones: In 1912, in an effort to standardize birthstones, the (American) National Association of Jewelers (now called Jewelers of America) met in Kansas and officially adopted a list. The Jewelry Industry Council of America updated the list in 1952 by adding Alexandrite for June, citrine for November and pink tourmaline for October. They also replaced December's lapis with zircon and switched the primary/alternative gems for March. The American Gem Trade Association added tanzanite as a December birthstone in 2002. In 2016, the American Gem Trade Association and Jewelers of America added spinel as an additional birthstone for August. Britain's National Association of Goldsmiths created their own standardized list of birthstones in 1937.
Eastern Traditional Birthstones: Eastern cultures recognize a similar range of gemstones associated with birth, though rather than associating a gem with a birth month, gemstones are associated with celestial bodies, and astrology is employed to determine the gemstones most closely associated with and beneficial to a particular individual. For example, in Hinduism there are nine gemstones associated with the Navagraha (celestial forces including the planets, the sun, and the moon), known in Sanskrit as Navaratna (nine gems). At birth, an astrological chart is calculated, and certain stones are recommended to be worn on the body to ward off potential problems based on the place of these forces in the sky at the exact place and time of birth.
- Mystical birthstones: Based on the Tibetan birthstone chart dating back thousands of years. A mystical birthstone represents the spiritual world, which is why some people prefer these types of birthstones to modern ones.
- Ayurvedic birthstones: Ayurvedic birthstones date back to ancient Indian culture, who believed in specific stones having certain healing powers. They date back as far as 1500 B.C., and are linked closely with the ancient practices of Indian medicine.
Informational sources for the birthstone informational pages include and are not limited to: Mindat, Smithsonian, Gem Society, GIA, "Fifty Minerals that Changed the Course of History" by- Eric Chaline, "The Curious Lore of Precious Stones" by- George Frederick Kunz, Wikipedia, American Gem Society, Geology.com, my own research summaries (Kai)