Igneous
Sodalite Syenite (popularly known as Yooperlite)
Sodalite-rich Syenite (composed of alkali feldspar and sodalite)
Hardness: 5.5-6 on the Mohs scale. Color: Grayish-black under normal light, vivid glowing orange/red under long-wave ultraviolet light. Luster: Vitreous to greasy. Crystal structure: Hexagonal/Cubic (inclusions). Cleavage: Poor.
- Hardness
- 5
- Luster
- Vitreous to greasy
Identified More igneous →
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Physical properties
Hardness: 5.5-6 on the Mohs scale. Color: Grayish-black under normal light, vivid glowing orange/red under long-wave ultraviolet light. Luster: Vitreous to greasy. Crystal structure: Hexagonal/Cubic (inclusions). Cleavage: Poor.
Formation & geological history
Formed from alkaline magma reaching the Earth's crust. These specific specimens were transported by glaciers during the Pleistocene epoch from Canada to the Upper Peninsula of Michigan, where they are found as water-worn pebbles.
Uses & applications
Primarily used as a collector mineral and in the lapidary arts for making jewelry, polished stones, and decorative spheres due to its unique fluorescence.
Geological facts
Was first 'discovered' and branded in 2017 by Erik Rintamaki on the shores of Lake Superior. The 'glow' is caused by trace amounts of the mineral sodalite reacting to UV light.
Field identification & locations
Identify in the field using a long-wave 365nm UV flashlight at night on gravel beaches. Common locations include the southern shores of Lake Michigan and Lake Superior. Collectors look for high concentrations of fluorescent 'flakes' or solid glowing patterns.
