Anthracite Coal

Hardness: 2.5–3.0 on the Mohs scale. Color: Deep black to dark grayish-black with a metallic or sub-metallic shiny luster. Fracture: Conchoidal to uneven. Specific gravity: 1.3–1.8. Crystal structure: Amorphous (non-crystalline carbon matrix).

Formed from compressed organic plant matter subjected to high pressures and temperatures over millions of years (primarily Carboniferous period). It represents the highest grade of coalification with the highest carbon content (over 86%). The coordinates correspond to Burgundy/Autun region in France, known historically for Carboniferous coal basins and oil shales.

Historically used as a high-efficiency smokeless heating fuel and industrial energy source. Today, small specimens are used for educational collections, mineral study, and specialized carbon filtration production.

Anthracite burns with a clean, hot, nearly smokeless blue flame due to its low moisture and volatile matter content. Unlike lower grades of coal such as lignite or bituminous coal, it does not easily soil fingers when handled because of its high density and sub-metallic luster.

Can be identified in the field by its jet-black color, glassy/metallic sheen, vitreous conchoidal fracture surfaces, and low density relative to stone. Commonly found in folded geological strata and historic coal-mining regions like the Autun basin in France or eastern Pennsylvania in the USA.