October Birthstone
October has two birthstones: Opal (the iridescent play-of-color gem) and Tourmaline (the rainbow-spectrum mineral), each with rich history and symbolism.
Opal
Primary Birthstone Mohs 5.5–6.5Opal is the primary birthstone for October. Prized for its extraordinary play-of-color — a shifting rainbow of spectral hues — no two Opals are alike. The name derives from the Sanskrit upala, meaning precious stone, and was later adopted by the Romans as opalus. Opal symbolizes hope, creativity, and innocence.
Month
October
Hardness
5.5–6.5 Mohs
Crystal
Amorphous
Composition
SiO₂·nH₂O
Opal Color Varieties
White Opal
Light body with pastel play-of-color. The most common variety; mined mainly in South Australia.
Black Opal
Dark body tone makes colors appear vivid and dramatic. The rarest and most valuable type; found primarily in Lightning Ridge, NSW.
Boulder Opal
Opal in its natural ironstone host rock. Found in Queensland; often cut with the host rock still attached.
Crystal Opal
Transparent to semi-transparent with play-of-color visible through the body. Highly prized for its clarity.
Fire Opal
Vivid orange, yellow, or red body color from Mexico. May or may not show play-of-color.
Andean Opal
Opaque blue-green to pink stone from Peru; typically used as a decorative gemstone without play-of-color.
History & Lore
- Ancient Romans regarded Opal as the most precious and powerful gemstone because it contained the colors of all others.
- Arab traders believed Opal fell from the heavens in flashes of lightning, which gave it its spectral fire.
- Shakespeare referenced Opal in Twelfth Night: "Now, the melancholy god protect thee; and the tailor make thy doublet of changeable taffeta, for thy mind is a very opal."
- Australia produces over 90% of the world's precious Opals, with Lightning Ridge and Coober Pedy being the most famous sources.
- Queen Victoria championed Opal jewelry throughout the 19th century, helping restore its reputation after a superstition spread by a Walter Scott novel portrayed it as unlucky.
Care & Cleaning Tips
Do
- •Wipe with a soft, damp cloth
- •Store in a padded jewelry box
- •Keep away from other gems that may scratch it
- •Apply cosmetics and perfume before putting on Opal jewelry
Don't
- •Use ultrasonic or steam cleaners
- •Soak in water or harsh chemicals
- •Expose to extreme heat or sudden temperature changes
- •Store in airtight containers for long periods (Opal contains water)
Opal vs. Tourmaline at a Glance
| Property | Opal | Tourmaline |
|---|---|---|
| Hardness | 5.5–6.5 Mohs | 7–7.5 Mohs |
| Durability | Fragile; avoid impact | Good; suitable for daily wear |
| Color | White, black, fire | Every color imaginable |
| Special trait | Play-of-color | Widest natural color range |
| Main sources | Australia, Ethiopia | Brazil, Sri Lanka, Africa |
| Price range | $30–$10,000+ / ct | $10–$3,000+ / ct |
| Symbolism | Hope, creativity | Compassion, love, peace |
| Anniversary | 14th wedding year | Not traditionally assigned |
Summary
October has two birthstones: Opal (the iridescent play-of-color gem) and Tourmaline (the rainbow-spectrum mineral), each with rich history and symbolism.
How it works
- Choose a birthstone tab — Opal or Tourmaline — to explore that gem.
- Read the overview card for history, meaning, and lore.
- Browse the color varieties section to see available hues.
- Check the quality and grading tips before buying.
- Review the care and cleaning guide to keep your stone brilliant.
Use cases
- Find the perfect October birthday gift for a friend or family member.
- Learn the symbolism and lore behind Opal and Tourmaline.
- Identify which color variety of Tourmaline matches a personal style.
- Understand how to care for an Opal or Tourmaline piece of jewelry.
- Settle the question of which gem is the "real" October birthstone.
- Research gemstone options before visiting a jeweler.
Frequently Asked Questions
Last updated: 2026-06-10 ·
Reviewed by Nham Vu