Anthracite is the hardest, purest, and cleanest-burning type of coal. While regular coal might crumble in your hands and leave black dust everywhere, anthracite is glossy, dense, and almost looks like polished black stone. It contains very few impurities and burns with hardly any smoke, making it much cleaner than softer coals.

During the 1800s and early 1900s, anthracite was precious fuel, especially in American cities. Families heated their homes with anthracite stoves, and the coal burned so hot and clean that it was perfect for city apartments where smoky chimneys would have been a problem. The richest deposits in America were found in northeastern Pennsylvania, and mining towns grew up around these valuable seams of black rock.

Anthracite forms deep underground over millions of years, where tremendous heat and pressure transform softer coal into this ultra-hard form. It's so compressed that it contains more carbon than any other type of coal. Think of it like the difference between soft clay and fired pottery: both start as similar materials, but heat and pressure create something much harder and more useful.