The United States, Britain and Japan each keep their own official list, and India and Thailand have the much older tradition of nine gems. Pick a month to see every list side by side, with what each stone needs at the bench.
Lighter names are alternatives. Gold tags mark stones added to the US list after 1912; red tags mark Japan's 2021 additions.
The month in detail
October
Every stone of the month, at the bench
Wear guide: JewelLoop bench guidance from each stone's hardness (Mohs) and toughness (GIA). Everyday ring: takes daily knocks. Ring with care: fine in a ring with a protective setting and some care. Pendant or earring: soft, brittle or porous; in a ring choose a bezel and expect wear.
In India and much of Southeast Asia, gems belong to the nine celestial bodies of Vedic astronomy rather than to months. The Indian navaratna sets a ruby for the Sun in the centre with the other eight around it; Thailand's nine gems (nopphakao) follow the same idea and gave their name to the Order of the Nine Gems, founded by King Mongkut in 1861.
United States: GIA, Birthstones by month (current list). History: list adopted 1912 by the National Association of Jewelers (now Jewelers of America); alexandrite, citrine, tourmaline and zircon added 1952; tanzanite 2002; spinel 2016 by the American Gem Trade Association and Jewelers of America (National Jeweler, "Rocks on: the evolution of the birthstone list", 29 Aug 2016).
United Kingdom: National Association of Jewellers (formerly the National Association of Goldsmiths, whose first list dates from 1937), Birthstones, traditional and alternative stones.
Japan: list revised on 20 December 2021 by the National Association of Jewelry Wholesalers (全国宝石卸商協同組合), first revision since the 1958 list; 10 stones added, 29 in all (Kobe Shimbun, 2021-12; zho.or.jp; Yamanashi Jewelry Museum, The Joys of Jewelry 5: Birthstones).
Navaratna: classical arrangement as given in the Mani-mala (S. M. Tagore, 1879) and Jataka Parijata (2.21); Sanskrit names from the same. Thailand: the nine gems of the Most Illustrious Order of the Nine Gems (1861).
Hardness and wear: Mohs values and toughness from GIA's gem descriptions, as in the JewelLoop gemstone reference table. Colours on this page are representative, not measurements. Anniversary stones are not shown: no single trade body sets them.