Facies
All of the geological characteristics of a particular rock unit.
The overall characteristics of a rock unit that reflect its origin and differentiate the unit from others around it. Mineralogy and sedimentary source, fossil content, sedimentary structures and texture distinguish one facies from another.
For further information: A definition of Sedimentary Rocks, Facies, Transgressions and Regressions, Walther's Law by Pamela J. W. Gore, Georgia Perimeter College, Clarkston, GA