The Riverstone quarry is located in La Represa, deep in central Argentina, situated between the Pampas and the Andes mountain range. Riverstone is a Phyllite stone formed within a pre-Cambrian rock sequence around 640 million years old.
It is the only source of this type of stone locally, and there are only a few sources of Phyllite stone available worldwide, making commercially accessible Phyllite stone extremely rare.