Birthstones by Month: The Complete Guide

Birthstones assign a gemstone to each month of the year, a tradition with roots going back centuries but formally standardised in the West in 1912 by the American National Retail Jewelers Association (now Jewelers of America). The list has been revised several times since — most recently in 2016, when spinel joined peridot as an August stone.

The modern birthstone list

Why some months have more than one stone

Where a month lists multiple stones, it's because a newer alternative was added alongside — not instead of — the traditional choice, usually to offer a more available or affordable option. Alexandrite (June) and spinel (August) are both comparatively rare and expensive in fine quality, so pearl/moonstone and peridot remain the more commonly worn choices for those months in practice.

Traditional vs modern differences

A handful of months use a genuinely different stone on the older, pre-1912 traditional list than on the modern one. The clearest example is March: the modern list uses aquamarine, but the traditional stone is bloodstone, a dark green jasper flecked with red jasper or iron oxide inclusions. August traditionally used sardonyx before peridot became the modern standard.

What to look for buying each

• Garnet, amethyst, citrine, topaz — widely available and affordable in fine quality; focus on strong, even colour saturation over rarity claims.
• Aquamarine — clarity matters more than depth of colour; the best stones are eye-clean with a clean, cool blue.
• Emerald, ruby, sapphire — see our full sapphire and ruby guides; treatment disclosure (heat, oil, fracture-filling) materially affects both price and durability.
• Pearl — buy for surface quality (blemish-free, high lustre) and consistent nacre thickness over sheer size.
• Peridot, spinel, tourmaline, alexandrite, tanzanite — all benefit enormously from independent lab certification once you're spending above a few hundred dollars a carat; see our cert lab guide.
• Opal — buy in person or from a dealer offering a strong returns policy; photos struggle to capture play-of-colour accurately, and stability (avoiding crazing) depends on how the rough was cut.
• Turquoise, zircon — ask specifically whether turquoise has been stabilised (very common and acceptable if disclosed) and whether zircon has been heat-treated for colour (near-universal, and standard practice).

Related reading

• How gemstones are priced
• Mohs hardness scale: which gemstones are safe for everyday wear
• Browse the Gemstone Encyclopedia

Source: birthstone history and the modern/traditional list per the International Gem Society and GIA (gia.edu).