![Fluorescent Sodalite (Yooperlite) (Syenite clast containing fluorescent sodalite [Na8(Al6Si6O24)Cl2]) — igneous](https://media.rock.id/fluorescent-sodalite-yooperlite-93f97893-1362-4786-a73e-959d0c7c2791-compressed.jpg)
igneous
Fluorescent Sodalite (Yooperlite)
Syenite clast containing fluorescent sodalite [Na8(Al6Si6O24)Cl2]
AI-generated identification · may be incorrectHardness: 5.5 - 6 on the Mohs scale. Natural color: dull gray, mottled beige to brown under visible light. Under longwave ultraviolet (UV) light (around 365 nm), it fluoresces a bright orange to yellow-orange glow due to disulfide impurities in the sodalite. Luster: vitreous to greasy.…
- Hardness
- 5
- Color
- dull gray, mottled beige to brown under visible light
- Luster
- vitreous to greasy
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Physical properties
Hardness: 5.5 - 6 on the Mohs scale. Natural color: dull gray, mottled beige to brown under visible light. Under longwave ultraviolet (UV) light (around 365 nm), it fluoresces a bright orange to yellow-orange glow due to disulfide impurities in the sodalite. Luster: vitreous to greasy. Crystal structure: isometric (sodalite component).
Formation & geological history
Formed in silica-undersaturated alkaline igneous intrusions (nepheline syenites), notably transported by Pleistocene continental glaciers from the Coldwell Alkaline Complex in Ontario, Canada, and deposited along the glacial drift and beaches of the Upper Peninsula of Michigan.
Uses & applications
Popular as mineral collector specimens, decorative tumbled stones, cabochons for UV-reactive novelty jewelry, and educational demonstration pieces.
Geological facts
Commonly known by the trademarked name 'Yooperlite,' these rocks were discovered in 2017 along the shores of Lake Superior by Erik Rintamaki, who noticed their bright fiery orange glow when using a 365 nm UV flashlight at night.
Field identification & locations
Best identified by walking Lake Superior gravel beaches at night using a filtered 365 nm UV light, where the otherwise nondescript grayish syenite pebbles glow vividly with bright orange patterns.
