📜 Key facts
| Age | Varies by deposit; Burmese rubies formed in marble around 30–40 million years ago |
|---|---|
| Origin & sources | Myanmar (Mogok), Sri Lanka, India, Vietnam and East Africa. The 138.7-carat Rosser Reeves star ruby is at the Smithsonian. |
| Composition | Corundum (Al₂O₃) coloured by chromium, with oriented rutile needles |
How it forms
Like star sapphire, rutile needles separate out in three directions as the crystal cools. A cabochon cut gathers the reflected light into a six-rayed star.
Mineral data: see Ruby.
🌍 Where it's found
- Type locality
- Notable source / deposit
- Country of origin
Marker positions are approximate (region or locality level). Type localities from Wikidata; notable sources curated by Crystopedia.
Learn more
Mineral variety
Red
RootHeart
Healing crystal



