August Birthstone: Peridot Meaning, Color & History

Peridot illustration

Peridot is one of the only gems that occasionally arrives from somewhere other than the ground: most of it is carried up from deep within Earth’s mantle by hardened lava, but rare examples have actually been found in meteorites. That’s a genuinely unusual origin story for a birthstone, and it’s just the first of three completely unrelated August stones, since spinel and sardonyx round out the month with their own distinct colors, histories, and price ranges.

August at a glance

• Birthstones: peridot, spinel, and sardonyx
• Peridot: green and formed under extreme conditions
• Spinel: many colors, including red; 8 Mohs
• Sardonyx: the original August birthstone, with a history of more than 4,000 years
• Practical choice: spinel is the strongest all-round ring candidate

Peridot: forged deep, worn light

Peridot is the gem variety of olivine, and its green comes from iron within the mineral itself rather than a trace impurity, which is a bit unusual among colored gems. Its color runs from yellowish lime to olive green, a distinctive palette that gives a peridot gift a different personality from emerald or green tourmaline. At 6.5 to 7 on the Mohs scale with only fair to good toughness, it’s softer than the other two August stones, so it’s not the stone for a carefree sports ring. Warm soapy water is the sensible cleaning method, and a protected, low setting helps if it’s going on a hand that stays busy.

Spinel: the impostor that isn’t one

For centuries, red spinel was mistaken for ruby, most famously in the Black Prince’s “Ruby” set into Britain’s Imperial State Crown, which is actually a large red spinel. The two weren’t chemically distinguished until the 18th century, which explains why a red August stone might look like July’s ruby without being ruby at all, and why a good jeweler always identifies spinel as spinel rather than a lesser stand-in.

At 8 Mohs, spinel is generally durable for rings and other everyday jewelry, and it’s stable in light and most chemicals, though high heat can fade some colors. Warm soapy water is always safe, and ultrasonic or steam cleaning can be used too, though fractures make those methods a bit riskier. It also comes in an impressively wide color range beyond red: pinks, blues, violets, grays, and more, some of it natural color and some treatment-derived, so it’s worth asking which you’re getting.

Sardonyx: the original August stone

Sardonyx is banded chalcedony, usually layered with brownish-red sard and white onyx, and GIA credits it as August’s original birthstone, with a documented history stretching back more than 4,000 years. It’s typically carved or shaped into a cabochon rather than judged like a transparent faceted gem, so a crisp cameo or a distinct, well-defined band pattern matters more here than a conventional clarity grade. It’s worth asking about dyeing if a color or banding pattern looks unusually uniform.

Comparing price across three unrelated stones

Don’t expect one “August price.” Peridot is judged on its green color, transparency, cut, and size. Spinel’s value depends on color, clarity, and whether that color is natural. Sardonyx is priced on its color, cut or carving, condition, and availability. Ask a seller to name the specific material rather than settling for “August birthstone” as a description, since fine red or cobalt-blue spinel, vivid peridot, and intricate antique sardonyx jewelry all live in entirely different markets.

Why August, and the calendar tradition

All three stones share August’s spot in the modern list rather than being divided across specific days, and none of it maps onto Western zodiac traditions. The birthstones hub covers the rest of the year, and the birthday calculator has more on your own date.

Matching each stone to the piece

Choose peridot for its yellowish-green to olive palette, best suited to earrings, pendants, or a well-protected ring; check its color in daylight as well as indoor light, since an overly brown or dark stone won’t deliver the fresh green you’re expecting. Choose spinel when daily wear and a broad color range matter most, and confirm whether its color is natural and whether the stone itself is natural or laboratory-grown, since spinel can be grown in a lab. Choose sardonyx for an opaque, graphic, historic look, ideal for a signet ring or cameo.

Whichever you pick, remember these three stones aren’t a ranking of “real” versus “backup” August birthstones, they’re three materially distinct ways to mark the same birthday, and the right choice comes down to the look, durability, and budget that actually fit the person wearing it.