SOIL.

A soil diagram chart is used to find the percent makeup of soil. By looking at the the percentages of silt, clay, and sand in the soil sample you have, you can classify it. All you do is take the numbers given and follow the corresponding lines to the middle, in which point you will find your classification. 

This is the Munsell Color System. Developed by a professor named Albert H. Munsell, this chart basis its system on the chroma, hue, and value of a sample. 

This image is of the Twelve Orders of Soil Taxonomy. The orders are alifisol, andisol, ardisol, entisol, gelisol, histisol, inceptisol, mollisol, oxisol, spodosol, ultisol, and vertisol. The most common order in Georgia is ultisol with big deposits of alfisol and inceptisol.