Anthracite is a better type of coal than bituminous, anthracite is the best type of coal because it is the purest type of coal as it has the highest amount of carbon content p â¦ resent in it. It is made up of 90-95% of carbon content, so, it has a higher calorific value and burns without a smoke.
The NGC Coin Price Guide is a complete catalog of coin values for US and World coins from 1600 to date, compiled from a variety of numismatic sources. Sign In Join
NGC Coin Grading Scale. NGC uses the internationally accepted Sheldon grading scale of 1 to 70, which was first used in the United States in the late 1940s. This scale was adopted by NGC when it began operations in 1987 and is considered to be the industry standard. Below are NGC's grading standards for each numeric grade as well as major strike types and designations. Certain coins have surface problems that preclude numeric grading by NGC.