Petit Granit (also known by a variety of names including: Nero Belga, Granit de Flandre, Pierre Blue, Blue Stone, Belgian Granite, Belgian Blue Limestone, Arduin) is, despite its name, a grey-bluish limestone, rather than being a true Granite.It is mined exclusively in Belgium, where use of the name Petit Granit is subject to an Appellation d’Origine Locale (Local Appellation of Origin ...