Within the British birthstone tradition Lapis lazuli appears as one of the December alternates, alongside turquoise, tanzanite, and zircon. The British list, maintained by the National Association of Jewellers (NAJ, formerly the National Association of Goldsmiths), has historically been more conservative than the American Jewelers of America list, which added tanzanite as a December birthstone in 2002. Lapis is not on every published version of either list, but appears in trade reference works as a long-recognised December alternate, particularly in older editions where turquoise was the dominant choice and lapis was offered as a darker, more saturated variant.

Origin of the association

The British birthstone list as currently used descends from a 1937 list compiled by the NAG and updated periodically since. The medieval and Renaissance traditions of stone-month assignment varied widely; Tiffany & Co.'s 1870 poem and the 1912 Jewelers of America list standardised the modern American convention, with the British and other national lists branching off and varying in details. Lapis, with its long history as a precious blue stone in European jewellery, was an obvious candidate for inclusion as a winter-birth stone alongside the lighter blue of turquoise and the colourless brilliance of zircon.

Modern usage

For a British retailer, lapis as a December birthstone is a useful option for customers who want a saturated blue at a price below tanzanite. The trade convention is to disclose any treatment (dye, polymer impregnation) in writing, to confirm that the material is natural lapis lazuli rather than dyed howlite, reconstituted material, or Gilson synthetic, and to recommend protective settings given lapis's modest hardness of 5 to 5.5 on the Mohs scale. Care advice is the same as for any lapis: avoid acids, ultrasonic and steam cleaning, and prolonged sun exposure.