Birthstones by month
All twelve months, modern and traditional stones, colours, birth flowers and hardness — in one chart.
| Month | Modern stone | Traditional | Colour | Birth flower | Mohs |
|---|---|---|---|---|---|
| January | Garnet | Garnet | Deep red | Carnation | 6.5–7.5 |
| February | Amethyst | Amethyst | Purple | Violet | 7 |
| March | Aquamarine | Bloodstone | Pale blue to sea green | Daffodil | 7.5–8 |
| April | Diamond | Diamond | Colourless | Daisy | 10 |
| May | Emerald | Emerald | Green | Lily of the Valley | 7.5–8 |
| June | Pearl, Moonstone, Alexandrite | Pearl | White, cream and colour-shifting | Rose | 2.5–4.5 |
| July | Ruby | Ruby | Red | Larkspur | 9 |
| August | Peridot, Spinel | Sardonyx | Yellow-green | Gladiolus | 6.5–7 |
| September | Sapphire | Sapphire | Deep blue | Aster | 9 |
| October | Opal, Tourmaline | Opal | Iridescent and multicoloured | Marigold | 5.5–6.5 |
| November | Topaz, Citrine | Topaz | Yellow to amber | Chrysanthemum | 8 |
| December | Turquoise, Zircon, Tanzanite | Turquoise | Blue to blue-violet | Narcissus | 5–6 |
Mohs hardness is shown for the first modern stone of each month. It matters: anything under 7 will scratch in a ring worn daily. What that means when buying →
Two lists, both correct
The modern list was standardised by American jewellers in 1912 and amended twice since — tanzanite joined December in 2002, spinel joined August in 2016. The traditional list is older and never went away. When a month shows two stones, that is usually the two lists disagreeing rather than a mistake.
Where birthstones came from
The oldest thread runs back to the breastplate described in the Book of Exodus, set with twelve stones for the twelve tribes of Israel. First-century writers connected those twelve to the twelve signs of the zodiac, and the practice at that stage was to own all twelve and wear each during its own period.
Wearing only the stone of your birth month is a much later habit — it appears in Poland around the eighteenth century and spread from there. The version most people know today is younger still: the National Association of Jewelers fixed the American list in 1912, and that commercial standard is what the trade has used since.
Month, or zodiac sign?
They are two different systems and they do not line up, because zodiac signs straddle two calendar months. Someone born on 10 October has October's opal by month and Libra's opal by sign — those agree. Someone born on 30 October has October's opal by month but Scorpio's topaz by sign.
Neither is more authentic. The zodiac list is older; the monthly list is what jewellers use. The full zodiac version is here.
What the stone is actually made of
Every stone page in this reference carries its chemical composition, crystal system, Mohs hardness and where it is mined. That is deliberate: most birthstone writing online repeats the same handful of adjectives without a single verifiable fact, and it is impossible to tell one page from another.
The traditional associations are here too, but labelled as traditional. They are worth knowing as cultural history — they are not claims about what a mineral does.
Common questions
What are the birthstones for all 12 months?
January garnet, February amethyst, March aquamarine, April diamond, May emerald, June pearl, July ruby, August peridot, September sapphire, October opal, November topaz, December turquoise. June, August, October, November and December each carry additional official stones.
Why does my month have more than one stone?
Usually because the modern and traditional lists disagree, or because a stone was added later to give a cheaper option. June is the extreme case with three: pearl is ancient, moonstone is affordable, and natural alexandrite is rarer than diamond.
Can I wear a birthstone that is not mine?
Nothing in the tradition forbids it. The original practice was to own all twelve and rotate through them — the one-stone-per-person rule is a later convention, and a commercially convenient one.
Which birthstone is the most expensive?
Per carat, fine ruby and Kashmir sapphire regularly outprice diamond. Natural alexandrite with a strong colour change is scarcer than all of them.