The "Rock of the Year" has been selected since 2007 by an expert board of trustees under the auspices of the Professional Association of German Geoscientists (BDG). With the nomination, rocks that are remarkable for their geological formation and economic importance are brought into the public interest.
The greywacke is a mostly gray sandstone in which poorly rounded and unsorted grains of sand are embedded in a very solid, fine-grained matrix. It is a very resistant rock that comes in many varieties. Greywackes are widespread in Saxony. Two geological periods of formation are distinguished. They are mainly found in northern Saxony, in the Vogtland and in the Görlitz Slate Mountains.