August is a three stone month on modern lists: peridot, spinel, and sardonyx. Peridot is the traditional pick and has held the spot for centuries; the jewelers association added spinel as a modern alternate in 2016 to recognise a stone whose quality and availability had been long understated.
Sardonyx, a banded chalcedony, appears on older lists and is still carried by some jewelers as the seasonal stone.
For a reader shopping for an August birthday, peridot is the easiest and most affordable pick. Spinel is the connoisseur’s choice at higher budgets. Sardonyx suits someone who likes warm earth tones and the look of carved or cabochon stones.
The three August birthstones
Top August gemstone picks
Peridot
Peridot is the gem variety of the mineral forsterite-fayalite, olivine, coloured by iron. Its yellow-green color is one of very few stones that show the same hue under any light. Important sources include Peridot Mesa in Arizona, Pakistan (Sapat), and Myanmar.
Historically, peridot was mined on the Egyptian island of Zabargad and was favoured by Cleopatra; some of the famous “emeralds” of Cleopatra were in fact peridot.
Spinel
Spinel is magnesium aluminium oxide, Mohs 8, and historically confused with ruby for centuries. The Black Prince’s Ruby in the British Crown Jewels is a famous red spinel. Spinel comes in an extraordinary range of colours: red, pink, violet, blue, lavender, orange, and the pure cobalt-blue spinel of Vietnam.
It is typically untreated, which makes it an attractive pick for buyers who prefer no-treatment stones.
Sardonyx
Sardonyx is a banded chalcedony with alternating layers of red-brown sard and white onyx. Romans carved it into signet rings; it is still used for cameos today. Sardonyx is opaque, cut as cabochon or carving, and carries a warm earthy character rather than brightness.
A short history of the August stone
Peridot mining on Zabargad is documented from ancient Egyptian times. Roman writers praised it. Crusaders brought peridot back to Europe, where some stones ended up in church treasuries labeled as emerald. Sardonyx has been used for intaglio and cameo work continuously from the Roman period through the Renaissance.
Spinel was formally distinguished from ruby only in the late eighteenth century, which is why so many historical “rubies” turned out on later analysis to be spinel.
Meaning and tradition
Practitioners have long associated peridot with light, cheer, and emotional warmth. Romans called it the evening emerald because its color holds under low light. Spinel carries a newer set of associations with renewal and energy. Sardonyx is traditionally linked with courage and clear communication in public life.
- Traditional associations are not medical advice.
- Peridot can scratch if stored alongside harder stones; store separately.
Is an August stone right for you?
- You love fresh yellow-green (peridot).
- You want an untreated stone with premium color (spinel).
- You like warm earth tones and carved jewelry (sardonyx).
- You want an August gift that reads different from common birthstones.
- You want deep saturation in a green (peridot is a softer yellow-green).
- You need the very hardest stone (peridot is 6.5 to 7).
- You dislike warm earthy palettes (sardonyx is all earth tone).
Gift ideas and pairings
For an August birthday, a peridot oval in yellow gold is the flattering traditional gift. Spinel in pink or red works beautifully as a ruby alternative at a third of the price.
Sardonyx cameo pendants are heirloom-friendly gifts. Peridot pairs with pearl for a calm August-June sibling piece and with amethyst for color contrast.
Zodiac overlap for August
August spans Leo (through August 22) and Virgo (from August 23). Leo leans warm and dramatic; peridot and ruby suit it well. Virgo is an earth sign often given sapphire, carnelian, or jasper; some Virgo readers prefer sapphire to the August peridot.