Rudstone
Rudstone is a type of carbonate rock.
The Dunham classification did not consider grain size as a criterion for the description of carbonate lithologies. In an attempt to rectify this perceived deficiency, Embry & Klovan introduced the terms rudstone and floatstone for coarse-grained allochthonous carbonates. Following a survey of the use of the Dunham classification, Lokier and Al Junaibi clarified the definition of a rudstone as "a carbonate-dominated rock where more than 10% of the volume is grains larger than 2 mm and these grains support the fabric of the rock."
