Birthstones by month, at a glance: garnet for January, amethyst for February, aquamarine for March, diamond for April, emerald for May, pearl or alexandrite for June, ruby for July, peridot for August, sapphire for September, opal or tourmaline for October, topaz or citrine for November, and tanzanite, turquoise or zircon for December. That's the modern list — below, a gemmologist's guide to each stone, which ones genuinely stand up to daily wear, and the proudly Australian entries on the calendar.
The birthstone chart
| Month | Modern birthstone | Alternatives | Daily-wear durability |
|---|---|---|---|
| January | Garnet | — | Good (6.5–7.5) |
| February | Amethyst | — | Good (7) |
| March | Aquamarine | Bloodstone | Very good (7.5–8) |
| April | Diamond | — | Exceptional (10) |
| May | Emerald | — | Good, with care (7.5–8, often included) |
| June | Pearl | Alexandrite, moonstone | Gentle wear only (pearl 2.5–4.5) |
| July | Ruby | — | Excellent (9) |
| August | Peridot | Spinel, sardonyx | Moderate (6.5–7) |
| September | Sapphire | — | Excellent (9) |
| October | Opal | Tourmaline | Gentle wear (5–6.5) |
| November | Topaz | Citrine | Very good (8), note cleavage |
| December | Tanzanite | Turquoise, zircon | Moderate (6–7) |
January to April
Garnet (January) is a family, not one stone — from the familiar deep red almandine to the vivid green tsavorite and the rare colour-shifting varieties. Honest, durable, and wonderful value in pendants and earrings.
Amethyst (February) is quartz in royal purple, once ranked with the cardinal gems until large Brazilian deposits made it accessible to everyone. Buy for evenness of colour.
Aquamarine (March) is beryl — emerald's sister — in glacial sea-blue, typically far cleaner than emerald and tough enough for regular wear. I've compared the two siblings in detail in Emerald vs Aquamarine.
Diamond (April) needs no introduction, though April babies may enjoy knowing why it sits alone at the top of the hardness scale — I've explained what "hardness 10" actually means. From studs to tennis bracelets, it's the birthstone that doubles as a lifetime investment in wearability.
May to August
Emerald (May) is chromium-green beryl, almost always carrying the internal "jardin" of fine inclusions that prove its nature. It rewards protective settings and a gentle life — glamour with house rules.
Pearl (June) is the only birthstone made by a living creature, and Australia's South Sea pearls from the north-west coast are the largest and most lustrous cultured pearls in the world. Pearls are soft — keep them for skin, not gym bags. June's alternative, alexandrite, changes colour from green in daylight to red under warm light and is rarer than diamond.
Ruby (July) is corundum with chromium fire — hardness 9, saturated red, and centuries of symbolism. With sapphire, it's one of the two coloured stones I recommend without hesitation for daily-worn rings.
Peridot (August) is one of the few gems formed not in the crust but in the mantle itself, brought up in basalt — a cheerful olive-green with real geological romance. August's alternative, spinel, is a connoisseur's gem hiding in plain sight.
September to December
Sapphire (September) deserves its reputation as the thinking person's engagement stone — and Australians don't need to import it. Our New England and Queensland gemfields produce inky blues, teals and one-of-a-kind parti stones; I've written a full guide to Australian sapphires.
Opal (October) is Australia's national gemstone, and around 95% of the world's precious opal comes from our fields — Lightning Ridge black opal above all. It's a gem for mindful wear rather than daily knocks; see my black opal guide for the whole story. October's alternative, tourmaline, spans practically every colour nature makes.
Topaz (November) in its honeyed "imperial" shades is a very different creature from cheap blue material; citrine, the sunny quartz alternative, keeps the month affordable. Topaz is hard (8) but has a cleavage plane — a competent setter matters.
Tanzanite (December) comes from a single hillside in Tanzania and shifts between blue and violet as it moves — save it for pendants and occasion rings. Zircon, the underrated alternative, is a natural stone (no relation to cubic zirconia) with fire approaching diamond's.
Choosing a birthstone piece that lasts
My rule of thumb: for anything worn daily on the hands — rings, stackers, bracelets — choose hardness 8 and up (diamond, sapphire, ruby, topaz, aquamarine) or set softer stones protectively in bezels. For earrings and pendants, anything on the list works beautifully, because they simply don't take the same knocks. And if the birthstone brief is a milestone gift — a first child's birth month, a fortieth birthday — a bespoke piece lets us build the story into the design rather than picking it off a shelf.
Birthstone FAQ
Do I have to use the modern birthstone list?
No — the lists have been revised repeatedly over the last century (the "modern" list dates to 1912 and has been amended several times since). Traditional alternatives are just as legitimate. Choose the stone that means something; the calendar is a starting point, not a rulebook.
Which birthstones are safe for everyday rings?
Diamond, sapphire and ruby without reservation; aquamarine and topaz with sensible settings. Opal, pearl, emerald and tanzanite prefer occasional wear or the protection of pendants and earrings.
What is Australia's national gemstone?
Opal — proclaimed in 1993, and fitting, since Australia supplies the overwhelming majority of the world's precious opal.
