August Birthstones

August's modern and traditional stones look almost like opposites at first — peridot is a clean, glassy yellow-green, carnelian a warm, waxy orange-red — but both share an unusual distinction: they're among the oldest gemstones with continuous documented human use anywhere in the world.

Peridot is gem-quality forsterite, the magnesium-rich end member of the olivine mineral group, and it's genuinely unusual among gemstones because it forms deep in the Earth's upper mantle rather than in the crust — some peridot has even been found inside pallasite meteorites, making it one of the only gem materials known to occasionally arrive on Earth from space. Ancient Egyptians mined peridot on the Red Sea island of Zabargad (once called Topazios by the Greeks, which is the actual historical source of confusion behind the otherwise unrelated word "topaz") as far back as 1500 BCE, working the deposit at night because the stone was said to be easier to spot by torchlight than by day.

Carnelian is a variety of chalcedony colored by iron oxide impurities (hematite specifically), ranging from pale orange to a deep brownish red sometimes called sard when very dark. It appears constantly in ancient Egyptian and Mesopotamian material culture — carved into amulets, seals, and scarabs — partly because it was believed to protect the wearer and partly because it takes an exceptionally sharp, fine engraving edge, making it a favorite medium for cylinder seals used to sign official documents in cuneiform-era administration.

The modern list actually added a second official August stone, spinel, in 2016 — the first change to the standard list in decades — specifically because fine ruby-red spinel had historically been mistaken for ruby for centuries (several "rubies" in European crown jewels turned out on modern testing to actually be spinel) and jewelers wanted to give the long-overlooked stone its own recognized place rather than remaining permanently in ruby's shadow.

August spans the second half of Leo and the first three weeks of Virgo. Peridot's bright, energetic green-yellow sits naturally with Leo's fire-sign associations in crystal tradition, while carnelian's warm orange has its own long-standing sacral-chakra and vitality associations that predate the zodiac pairing entirely.

Peridot is a relatively soft gem for regular ring wear (Mohs 6.5–7) and can be damaged by sudden temperature changes or contact with acids and perfumes, so it suits pendants and earrings better than an everyday work ring; carnelian, by contrast, is a tough, durable chalcedony well suited to daily wear.

Both stones — along with spinel, the modern list's newer addition — have their own dedicated crystal pages covering their full geology in depth; this page focuses on why August ended up with three genuinely different stones competing for the same slot.

Peridot has a genuine chemical sensitivity worth knowing before buying: household chemicals, chlorinated pool water, and even prolonged acid rain exposure can etch or dull its surface over years, since the olivine structure is somewhat more reactive than most other transparent gemstones — a good reason to remove peridot jewelry before swimming or cleaning.

Much of the carnelian sold commercially today is actually dyed agate rather than naturally colored carnelian — agate takes dye readily along its banding, and heat treatment or dye can turn pale, undesirable chalcedony into a convincing carnelian orange. This has been standard trade practice for so long (documented as far back as ancient Rome) that it's less a modern deception than a very old one, but it's still worth knowing when buying.

Fine, untreated red carnelian in the deepest sard tone remains genuinely harder to source than the dyed material now dominating the market, which is part of why sard specifically commands a price premium over ordinary commercial carnelian.