Fluorite x Bitumen - Minerva No. 1

This exceptional fluorite from the Minerva No. 1 Mine in southern Illinois exhibits the unmistakable golden-to-violet blue zoning and clarity that made this locality world-famous. Sharp cubic faces reveal a luminous amber core capped by rich blue-violet edges, with delicate internal wisps and speckles of bitumen inclusions visible just under the surface of the crystal, distinctly glowing under UV light. The interplay of color, transparency, and organic inclusions captures the unique hydrocarbon-rich environment that shaped Minerva’s most iconic specimens.

Highlights:

• Locality: Minerva No. 1 Mine, Cave-in-Rock Sub-District, Hardin County, Illinois, USA 🇺🇸 
• Color & zoning: Transparent golden core transitioning to deep violet margins.
• Inclusions: Organic bitumen — visible as dark wisps, UV-reactive under shortwave light.
• Crystal form: Well-developed cubic crystal with smooth, lightly etched faces and superb internal luster.

Dimensions & Weight:

• Weight: 57 g
• Size: 1.8 × 1.5 × 1.8 in

Collector Notes:

Fluorite from the Minerva No. 1 Mine is highly sought after for its sharp color zoning and distinctive bitumen inclusions, which occur only in select hydrocarbon-bearing pockets of the deposit. This piece exemplifies the locality’s finest qualities — gemmy clarity, saturated color contrast, and internal depth — making it a standout addition to any Illinois or worldwide fluorite collection.