Month 10 · gemstone almanac
October
birthstone
Opal is known for its 'play of color' - flashes of spectral hues that shift as the stone moves. This phenomenon results from ordered silica spheres diffracting light. Australia is a historically important source, while other deposits include Ethiopia, Mexico, and Brazil.
Share the October birthstone guide
Immediate answer
Opal and Tourmaline
- Modern list
- Opal · Tourmaline
- Traditional list
- OpalSame lead stone; the modern list adds options
- Hardness
- 5.5-6.5 on Mohs scale (fragile)
- Reference policy
- Primary sources over folklore summariesAlternatives remain visible when a source lists them
Which list are you being given?
October kept its stone but gained alternatives
Most pages that answer “what is the october birthstone” quote one list without saying which. There are two in common use: the modern American list standardised by the National Association of Jewelers in 1912 and revised since, and the older traditional list that preceded it.
| List | Stone(s) for October | Basis |
|---|---|---|
| Modern | Opal, Tourmaline | Standardised in 1912 and maintained since; used by current gemological guidesThe list this site leads with |
| Traditional | Opal | Older lists predating the 1912 standardisationStill the lead stone on both lists |
What changed: Opal is the older October stone. Tourmaline was added in 1952, largely because a transparent, faceted gem suited modern ring settings better than opal.
The modern list was designed around transparent, faceted gems so that jewellers could set several children's stones in one ring. That commercial motive, not a gemological discovery, is why some months changed. Later revisions added alexandrite and citrine in 1952, tanzanite in 2002, and spinel in 2016.
Neither list is more “correct”: a birthstone assignment is a published convention, not a property of the gem or of the month. If a gift matters, ask which list the recipient grew up with.
Gem facts
Identity, color, and durability
Opal is known for its 'play of color' - flashes of spectral hues that shift as the stone moves. This phenomenon results from ordered silica spheres diffracting light. Australia is a historically important source, while other deposits include Ethiopia, Mexico, and Brazil.
- Names in use
- Precious Opal · Fire Opal · Black Opal
- Mohs hardness
- 5.5-6.5 on Mohs scale (fragile)
Typical color palette
- #A8C8DC
- #FF4500
- #FFFFFF
- #000000
Symbolic tradition
Meanings and crystal traditions
Opal symbolizes hope, creativity, and imagination. Its unique play of color - displaying all the rainbow's hues - represents the full spectrum of human emotion and experience.
- Crystal traditions associate opal with creativity and inspiration
- Roman symbolism connected opal with hope
- Modern spiritual readings link opal with imagination and intuition
- Its changing colors are sometimes used as a symbol of emotional range
- These interpretations are traditions, not scientific effects
Interpretation label: Personality words such as creative, imaginative, hopeful, unique, emotional belong to symbolic birthstone readings. They are not traits caused by a gemstone or birth month.
Context
History and cultural variations
Ancient Romans considered opal the most precious gem, containing the beauty of all other stones. The name comes from Sanskrit 'upala' meaning precious stone. Australian Aboriginal legend says opal was created when the creator came to Earth on a rainbow.
Most precious gem, symbol of hope and purity
Creator's footprints, rainbow stone
Could make wearer invisible (superstition)
Considered bad luck (thanks to a novel)
Variation note: Historical beliefs are presented as beliefs. A source can document a tradition without proving a physical or medical effect.
Practical guide
Jewelry care and gift ideas
- Clean gently with damp cloth
- Avoid ultrasonic and steam cleaners
- Store with some moisture (opals can dry out)
- Protect from heat and sudden temperature changes
- Handle very carefully - opals are fragile
Care note: Treatments, inclusions, and settings can change safe cleaning methods. Ask a qualified jeweler when a stone's treatment history is unknown.
Budget ideas
Opal doublet pendant · Small opal earrings · Ethiopian opal ring
Mid-range ideas
Australian opal pendant · Opal bracelet · Boulder opal jewelry
Premium ideas
Black opal ring · Lightning Ridge opal · Large precious opal necklace