| By Popularity
| Alphabetical (What's This?)|
- Australian Opals & Outback Australia
Opal mining, opal photos, and the Opal Festival at Yowah.
- Gemstone Education: Opal
History of the stone that has a rainbow locked within.
- Gemstones: Opal
An essay from the U.S. Geological Survey.
- Opal (Hydrated Silica Glass)
Offers detailed physical description, images of specimens, and more.
- Opal Festival
Features a parade, mine safety demonstrations, competitions, heritage celebrations, and heaps of opals. Held annually at Coober Pedy, Australia.