Birthstones by Month
Every month has its gem — some have two or three. The chart below is the standard US list jewelers actually use: the modern stones (standardized in 1912 and extended as recently as 2016), the traditional stones of older lists, and each month's signature color. Months with a deep-dive guide are linked; we're publishing the rest month by month.
Two stones can both be “correct” for one month — a modern and a traditional — so if a chart elsewhere disagrees with a family heirloom, nobody is wrong. The guides explain how each month got its stones.
The birthstone chart
| Month | Modern birthstone | Traditional | Color |
|---|---|---|---|
| January | Garnet | Garnet | Deep red |
| February | Amethyst | Amethyst | Purple |
| March | Aquamarine | Bloodstone | Pale blue; dark green with red |
| April | Diamond | Diamond | Colorless |
| May | Emerald | Emerald | Green |
| June | Pearl, Moonstone, Alexandrite | Pearl | White & cream; color-change |
| July | Ruby | Ruby | Red |
| August | Peridot, Spinel | Sardonyx | Yellow-green |
| September | Sapphire | Sapphire | Blue |
| October | Opal, Pink Tourmaline | Opal | Play-of-color; pink |
| November | Topaz, Citrine | Topaz | Golden yellow |
| December | Turquoise, Tanzanite, Zircon | Turquoise, Lapis Lazuli | Blue |
Sources: the US trade list standardized in 1912, revised 1952, with tanzanite added to December (2002) and spinel to August (2016). Stone names link to our field guide where we have a full page.
Month-by-month guides
Deep guides published so far — each covers the month's stones in detail, the color, the history, and honest buying notes:
Where the birthstone list comes from
The idea is ancient — twelve stones on the breastplate of Aaron, later tied to the twelve months and signs — but for most of history every country and jeweler kept a different list. The chart used today is a trade standard: American jewelers agreed a single list in 1912, revised it in 1952, and the industry has extended it only twice since, adding tanzanite to December in 2002 and spinel to August in 2016.
That history explains the chart's quirks: months with three stones (June, August, December) simply accumulated additions over a century, and “traditional” columns preserve the older folk choices that the 1912 list replaced.
Frequently asked questions
What are birthstones?
Birthstones are gems traditionally associated with each calendar month — wear the stone of your birth month and it is 'your' gem. The idea traces back to the twelve stones of the biblical breastplate of Aaron, later mapped onto months and zodiac signs; the specific modern list is a trade standard first agreed by American jewelers in 1912.
Why do some months have two or three birthstones?
The 1912 list was revised in 1952 (adding stones such as alexandrite for June and citrine for November) and extended twice since — tanzanite joined December in 2002 and spinel joined August in 2016. Additions gave buyers durable or affordable alternatives alongside soft or expensive traditional stones, and no stone has ever been removed, so several months now carry multiple official gems.
What is the difference between modern and traditional birthstones?
The modern list is the standardized trade list started in 1912 and maintained by US jewelry associations; traditional (or ancient) lists are the older folk assignments that varied by country and era. For most months they agree — for a few, like March (aquamarine modern, bloodstone traditional) and December (turquoise and lapis on older lists), both answers are correct.
Are birthstones the same as zodiac stones?
No — zodiac stone lists assign gems to star signs (which straddle two calendar months) and vary far more between sources. Month birthstones are the standardized list jewelers actually use. If you were born at the edge of a month, you simply have a claim to both months' stones.
Which birthstone is the rarest?
Of the official stones, fine alexandrite (June) is generally the rarest and most expensive per carat, followed by top tanzanite (December) — a gem mined commercially in only one small area of Tanzania. Rarity applies to fine quality, though: affordable grades of almost every birthstone exist.