Nivelstein sandstone

Nivelsteiner sandstone is a fine-grained Tertiary sandstone that originates from the area of the Worm valley in the border area between Dutch South Limburg and Germany. It is named after the vanished town and quarry of Nivelstein, just across the border at Kerkrade near Herzogenrath. It is an extremely pure, highly porous white sandstone. The sandstone occurs as kitted banks in Miocene beach deposits, which are called "silver sands".
It was already mined as a building material by the Romans in opencast mining near Nivelstein and was used until the Middle Ages. Today, it is extracted above ground in the Nivelstein and Hochfeld quarries for the raw materials quartz sand and quartz gravel.

Wikipedia