Anthracite Coal, commonly known as white coal or red coal is a kind of the highest degree of coalification coal,  carbon content over 90%, generally no glue layer thickness,  the calorific value of about 6000-6500 kcal/kg. Anthracite can be divided into the kinds of standard coal and anthracite  filter material, which is made of high quality carbon block of standard coal by selection, crushing,  screening of processed products,  more than for double and three layers of filtering. Anthracite filter material has good solid Hugh particles keep  ability, can improve the ability of suspended particle removal, apply to water treatment industry.

Stone are often used for building rubble walls and ran- dom courses. The skill in using cobbles for walls or footings comes with practice in matching and grading and is, in addition, assisted by gravity: the cobbles are rather dropped than "placed" or tamped into position, when building a wall or footing.