In geology, a conglomerate is a rock consisting of other stones that have been cemented together. Conglomerates are sedimentary rocks consisting of rounded clasts and are thus differentiated from breccias, which consist of angular clasts.
A spectacular example of conglomerate, the Crestone Conglomerate, may be viewed in and near the town of Crestone, Colorado at the foot of the Sangre de Christo Range in Colorado's San Luis Valley. The Crestone Conglomerate is a metamorphic rock statum and consists of tiny to quite large rocks that appear to have been tumbled in an ancient river. Some of the rocks have hues of red and green.
When a conglomerate is formed deep within alluvial fans in desert environments, the resulting rock is often called a fanglomerate.