Assertion: anthracite's impurity | /r/HasProperty | moisture
Facets:
Source sentences:
text: They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles).
text: These grades are the purest forms of coal, having the highest degree of coalification, the highest carbon and energy content and the least impurities (moisture, ash and VM).