August Birthstones: Peridot, Spinel & Sardonyx - Complete Guide [2025]

Born in August? You’re one of the rare months with three birthstones, each revealing a different facet of your personality.

Peridot, bright and luminous, has been called the “gem of the sun.” Formed in volcanic fire and found even in meteorites, it symbolizes renewal, growth, and the ability to bring light where others see darkness.

Spinel represents transformation. Once mistaken for ruby, it reflects the August-born gift of embracing authenticity and revealing one’s true colors rather than conforming to expectations.

Sardonyx, the oldest of the three, carries centuries of symbolism, strength, grounding, and protection. Its layered bands were worn by Roman soldiers and orators seeking courage and clarity.

Whether you connect with peridot’s renewal, spinel’s self-discovery, or sardonyx’s ancient strength, August’s birthstones reflect the complexity of who you are, not just the jewelry you wear.

What makes peridot different from other gemstones? It appears in only one color family. While most gems get their colors from trace elements, peridot's signature lime-green comes from iron as part of its core chemical structure. This means every peridot displays green, ranging from yellowish chartreuse to pure lime to deep olive.

What makes peridot unique?

Peridot is one of the rare gemstones that appears in only one color family. While most gems owe their hues to trace elements, peridot’s vibrant lime-green comes from iron within its very structure. Every stone is green, ranging from yellow-chartreuse to pure lime to deep olive.

Where does peridot come from?

Some of the rarest peridot is literally extraterrestrial, found inside pallasite meteorites. But most gem-quality peridot forms deep within volcanic environments. Major sources today include Pakistan, Myanmar, and Arizona. Ancient Egyptians mined it on Zabargad Island and revered it as the “gem of the sun” and some of Cleopatra’s so-called emeralds may actually have been peridot.

How durable is peridot?

Peridot is perfect for earrings, pendants, and rings worn occasionally. With protective settings, it can also work for everyday pieces. High-quality stones, especially from Pakistan, often show vivid lime color and impressive clarity, even in large sizes.

How much does peridot cost?

Peridot remains one of the most accessible August birthstones.

• Commercial yellow-green stones (1–5 cts) : $50–100 per carat

• Fine lime-green, eye-clean stones (2–5 cts) : $100–200 per carat

• Premium Pakistani material in larger sizes : $300–450 per carat

Its affordability makes bold, statement pieces possible without luxury-tier pricing.

Why was spinel mistaken for ruby?

For centuries, spinel and ruby were indistinguishable. They formed in the same regions and shared nearly identical color and appearance. History preserved this confusion: the “Black Prince’s Ruby” (170 ct) and the “Timur Ruby” (361 ct) in the British Crown Jewels are both red spinels, not rubies.

Modern gemology finally clarified the difference, prompting the American Gem Trade Association to officially add spinel as an August birthstone in 2016.

What colors does spinel come in?

Spinel is one of the most color-diverse gemstones.

• Red spinel rivals ruby’s intensity.

• Mahenge neon pink spinel from Tanzania glows with electric saturation.

• Cobalt-blue spinel from Sri Lanka is exceptionally rare.

• Orange, violet, steely gray, and even black spinel broaden the palette far beyond traditional birthstone hues.

This spectrum makes spinel a favorite for creative, contemporary designs.

How durable is spinel?

Spinel is highly durable, comparable to sapphire, making it suitable for engagement rings and everyday wear. Its resilience, combined with its natural color variety, is one reason it earned official birthstone status.

How much does spinel cost?

Spinel pricing varies widely by color and rarity:

• Commercial light colors : $100–300/ct

• Fine red and pink spinel (2–5 cts) : $800–3,000/ct

• Exceptional Mahenge neon pink : $3,000–8,000+ /ct

• Top-quality red spinel approaching ruby’s color : $5,000–15,000+ /ct

Unlike many rubies and sapphires, fine spinels are typically untreated, adding to their appeal among collectors.

What is sardonyx?

Sardonyx is a banded variety of chalcedony featuring alternating layers of reddish-brown sard and white or black onyx. Its striking contrast made it a favorite for cameos and intaglio seals, ancient artisans carved portraits and symbols that remained crisp when pressed into wax.

What is sardonyx’s historical significance?

In the ancient world, sardonyx symbolized strength and eloquence. Roman orators wore it to enhance clarity in speech, while soldiers carried it as a protective talisman in battle. Its long history gives it a sense of heritage and grounded symbolism unmatched by most modern gemstones.

How much does sardonyx cost?

Sardonyx is the most affordable of all birthstones.

• Simple beads or cabochons : $1–5

• Carved cabochons : usually under $20

• Antique cameos with fine craftsmanship : $50–500, with value based on artistry rather than rarity

For those who appreciate earthy tones and classical aesthetics, sardonyx offers meaningful August birthstone jewelry at a very accessible price point.

What defines quality in sardonyx?

High-quality sardonyx shows sharp, well-defined banding, clean separation between the red sard layers and the white or black onyx. Strong contrast is key: deep rust-red against crisp white is the traditional ideal. Today, sardonyx is most often found in beaded jewelry, men’s signet rings, and carved cabochons.

What do August birthstones symbolize? Traditional beliefs attributed distinct qualities to each stone, reflecting their physical characteristics and historical contexts.

Peridot

Linked to the sun god Ra in ancient Egypt, peridot was believed to ward off darkness and negativity. Today, it symbolizes renewal, growth, and vitality, fitting for a stone born from volcanic fire and transformed into luminous green crystal.

Spinel

For centuries mistaken for ruby, spinel inherited themes of passion, courage, and revitalizing energy. Its recognition as a distinct gemstone has made it a symbol of authenticity, truth, and embracing one’s multifaceted nature.

Sardonyx

Rooted in Roman tradition, sardonyx represents strength, protection, and eloquence. Its layered structure evokes stability and grounding qualities that appeal to those who appreciate August birthstones with deep historical resonance.

Which August birthstone should you choose? The answer depends on your priorities.

For Daily Wear

Spinel is the most durable (Mohs 8), making it ideal for engagement rings and jewelry worn every day.

Peridot can be worn daily with protective settings, but it’s best suited to pendants and earrings.

Sardonyx is durable enough for occasional rings but shines in carved pieces and signet designs.

For Color Preference

• Peridot: always green—perfect for nature lovers and vibrant, fresh palettes.

• Spinel: the most versatile, available in red, pink, blue, violet, orange, and black.

• Sardonyx: earthy, neutral tones with classic banding for those who prefer understated elegance.

For Investment Value

Fine spinel, especially Burmese red or Mahenge neon pink, shows strong collector demand and appreciation.

Peridot and sardonyx are more abundant, making them affordable but not typically investment-focused.

Recommended Settings

• Peridot & Sardonyx: benefit from protective bezels or halo settings that shelter edges.

• Spinel: durable enough for any design—prong, solitaire, tension, or modern exposed styles.

What makes August unique among birthstone months? August shares a distinction with only two other months, June (pearl, alexandrite, moonstone) and December (turquoise, tanzanite, zircon), in offering three official birthstone options. This variety reflects modern jewelry industry recognition that consumers value choice over rigid tradition.

Compared to other birthstone months

August stands out for its accessibility.

Peridot and sardonyx provide affordable options, while spinel offers a bridge into mid- to high-end gemstone territory, making August one of the most versatile months in terms of pricing.

Unique advantages of August birthstones

• Peridot is the only birthstone with extraterrestrial origins, found in rare meteorites.

• Spinel became an official birthstone in 2016, making it the newest addition to the modern list.

• Sardonyx has the oldest documented history, worn for over 4,000 years.

Together, they make August a month defined by variety, heritage, and individuality.