- Article
Gemmological Properties of Opals from Spencer, Idaho, USA
- Ugo Hennebois,
- Stefanos Karampelas,
- Emmanuel Fritsch,
- Maxence Vigier,
- Jean-Yves Mevellec,
- Nicolas Stephant,
- Quentin Dartois and
- Aurélien Delaunay
Fifteen opal samples of gem quality from the Spencer Opal Mines in Idaho (USA) were examined. These opals display play-of-colour, with three of them having a pink body colour. The analysis was conducted using standard gemmological tools, along with n...