August carries three official birthstones, each formed through a completely different process.
Peridot crystallises deep within the earth's mantle, sometimes arriving at the surface through volcanic activity. Spinel often hid in plain sight for centuries, mistaken for ruby in some of history's most famous jewels. Sardonyx forms in bands, layers of colour building one on top of another over time.
If you're wondering what the birthstone for August actually is, the answer includes all three: peridot, spinel, and sardonyx. Each brings a different colour, history, and character to the birthstone month of August.
This guide covers the meaning, origin, and care of all three August birthstones, along with jewellery options and ways to wear them.
Why Does August Have 3 Birthstones?
Peridot has served as the primary birthstone for August for centuries, tracing back to some of the earliest recorded birthstone lists.
Spinel joined more recently, added in part to correct a long history of mistaken identity. Many gemstones once catalogued as ruby, including several set into royal crowns, turned out to be spinel once modern gemmology could tell the two apart.
Sardonyx represents an older tradition. Ancient Rome prized the stone for its banded structure, often carving it into seals and signet rings, and it remained associated with August in earlier birthstone lists before peridot took the primary position.
Together, the three stones reflect different eras of how birthstones came to be assigned, ancient tradition, modern correction, and a gemstone whose brilliance earned it a permanent place on the calendar.
Peridot Birthstone
Peridot is one of the few gemstones that forms outside the earth's crust, crystallising within the upper mantle before volcanic activity carries it to the surface.
Peridot Birthstone Meaning & History
The word "peridot" comes from the Arabic faridat, which means gem. This August birthstone was essential in numerous ancient and medieval cultures. It first appeared in priests' jewelry in the second century BCE, then in chalices and cathedrals throughout medieval Europe. The peridot birthstone has also been used for ages as a protective charm, guarding the wearer from bad spirits and "terrors of the night."
Hawaiian tradition connects peridot to Pele, the volcano goddess, since the stone often appears in volcanic rock and even washes up as sand on certain black beaches. That volcanic origin gives peridot a more literal connection to the earth than most gemstones carry.
Where Is Peridot Found?
In the United States, Arizona is the primary supplier of this August birthstone. Massive volcanic eruptions thousands of years ago sent torrents of lava splattering across the desert landscape of what is now the San Carlos Apache Indian Reservation, where some Apache families have worked in mines for generations.
Peridot Birthstone Colour & Varieties
Iron within Peridot's crystal structure produces its signature green, ranging from a yellowish olive to a deep, saturated green with almost no undertone of blue or brown. The most valued stones carry a pure, vivid green with strong clarity.
Peridot ranks 6.5 to 7 on the Mohs hardness scale, softer than many popular gemstones, which makes it better suited to earrings and pendants than rings worn daily.
Peridot Birthstone Care & Cleaning
Warm water, mild soap, and a soft brush clean the peridot safely. Avoid ultrasonic cleaners and sudden temperature changes, both of which can stress the stone given its relative softness. Store peridot separately from harder gemstones to prevent scratching.
Spinel Birthstone
Spinel spent centuries in ruby's shadow, admired without ever receiving proper credit for its own qualities.
Spinel Birthstone Meaning & History
The Black Prince's Ruby, set into the British Imperial State Crown, is actually a 170-carat red spinel, one of many historical gems misidentified for hundreds of years before gemologists could reliably distinguish the two stones. Spinel's own reputation has grown considerably since that correction, now valued in its own right rather than as ruby's understudy.
Where Is Spinel Found?
Today, spinel comes from a range of sources. Tajikistan, Myanmar, Sri Lanka, Vietnam, Tanzania, and Pakistan produce the most significant supply, and Myanmar in particular yields some of the most striking hot pink and red spinel found anywhere.
Spinel Colour & Varieties
Spinel is available in a wide spectrum of colour varieties: black, red, pink, orange, purple, blue, and violet, with red and pink varieties commanding the highest value. Chromium produces the red and pink tones, while iron and other trace elements create the cooler blues and violets.
Spinel ranks 8 on the Mohs hardness scale, making it a genuinely durable choice for daily wear, comparable to sapphire in toughness.
Spinel Care & Cleaning
Spinel's hardness makes it forgiving. Warm water, mild soap, and a soft brush handle routine cleaning, and most spinel tolerates ultrasonic cleaners well, provided the stone hasn't been treated or fracture-filled.
Sardonyx Birthstone
Sardonyx builds itself in layers, each band a slightly different shade of the same family of colour.
Sardonyx Birthstone Meaning & History
Sardonyx belongs to the chalcedony family, formed from alternating bands of sard (a reddish-brown chalcedony) and onyx (typically black or white). Ancient Rome carved sardonyx into intaglios and seals, partly because the banded structure made forged impressions easy to detect, and partly for the way the contrasting layers caught light when carved.
Roman soldiers reportedly wore sardonyx into battle, believing the stone's grounded, layered strength offered protection.
Where Is Sardonyx Found?
India is the primary source of sardonyx today, with additional deposits in Brazil, Uruguay, and parts of the United States. The banding pattern varies by region, giving each source its own colour character.
Sardonyx Colour & Varieties
Sardonyx bands typically alternate between reddish-brown and white or black, though the width and contrast of the bands vary considerably from stone to stone. Jewellers often cut sardonyx to highlight the banding, particularly in cameo or intaglio work, where the layers create natural depth and contrast.
Sardonyx Care & Cleaning
Sardonyx ranks 6.5 to 7 on the Mohs hardness scale. Warm water, mild soap, and a soft brush clean it safely. Avoid harsh chemicals and prolonged sun exposure, both of which can affect the stone's colour over time.
August Birthstone Jewelry: Rings, Necklaces & Gifts
An August birthstone ring built around peridot brings a bright, consistent green that works well in both simple and detailed settings. Spinel offers more colour range for a ring, from deep black to cool violet, while sardonyx features a more structured, carved design that shows off its natural banding.
An August birthstone necklace built around any of the three stones works well as a pendant, letting the colour or pattern sit as a clear focal point. Spinel in particular makes a striking centrepiece thanks to its brilliance and durability.
For an August birthstone bracelet or August birthstone earrings, all three stones hold up well in smaller formats, with peridot and spinel both catching light effectively even at modest sizes.
August Birthstone by Date of Birth
Everyone born within the August 1-31 birthstone range shares the same three official gemstones: peridot, spinel, and sardonyx.
August keeps its birthstone assignment consistent across the full month, giving anyone born in August the freedom to choose whichever of the three stones suits their style.
Ways to Wear Your August Birthstone
Peridot's bright green pairs naturally with sterling silver, the cooler metal tone letting the stone's colour stand out clearly. Spinel works well in nearly any setting given its range of colours and strong durability, suiting both everyday pieces and statement jewellery. Sardonyx suits designs that let its banding show, carved pieces, cameos, or simple bezel settings that don't compete with the stone's natural pattern.
Where to Buy or Explore More Birthstones
Explore handcrafted sterling silver rings, pendants, necklaces, bracelets, and earrings built around peridot, spinel, sardonyx, and beyond. Continue through our birthstone series to discover the meaning, colour, and craftsmanship behind every month of the year.
Final Thoughts: Why Peridot, Spinel & Sardonyx Endure as August's Birthstones
Few birthstone months carry as much variety as August.
Peridot forms deep within the earth before volcanic activity brings it to the surface. Spinel spent centuries mistaken for a different gemstone entirely before earning recognition on its own terms. Sardonyx builds itself in bands, layer after layer, over a timeline measured in geological time rather than human memory.
Each stone earned its place in the August birthstone lineup differently, through ancient tradition, historical correction, and geological process. The August flower, the gladiolus, reflects that same variety, with tall, layered blooms in shades ranging from deep red to soft white.
The best August birthstone for you isn't necessarily the rarest or most valuable, it's the one whose colour and character you'll still want to look at years from now.
