Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-layer clay minerals, such as smectite and glauconite. Greensand is also loosely applied to any glauconitic sediment.
Greensand (glauconitic sandstone)
Occurrence of glauconitic siltstone in the Serra da Saudade ridge, in the Alto ParanaĆba region, Minas Gerais, Brazil
A sample of Cretaceous greensand from near Swanage, Dorset
Glauconite is an iron potassium phyllosilicate mineral of characteristic green color which is very friable and has very low weathering resistance.
Glauconite pellets and small fossils among quartz grains in greensand from the Dutch Pliocene