Photo: http://www.usgs.gov/blogs/features/slidedeck2/types-of-coal/anthracite-2/

Q: What makes rockhounds different from non-rockhounds?

A: They are happy to receive coal for Christmas.

Rockhounds love coal, and they love anthracite even more. Anthracite is a type of coal. It is very hard and burns slowly and cleanly due to its high carbon content and few impurities. It is rarer than bituminous coal (the soft, most common form of coal); in fact, less than 2% of the coal in the United States is anthracite. Also unlike bituminous coal, anthracite won’t leave soot on your fingers when you touch it.

There are four types of coal in all. The last two we haven’t covered yet are lignite coal and subbituminous coal, which have the lowest carbon content and are even softer then bituminous coal. Anthracite is the hardest and has the highest carbon content. Most of the coal in the United States is found in Colorado and Illinois, and is used primarily for making electricity and coke (coke is used by foundries to make iron and steel).