Ardennite is a very rare silicate named for the Type Locality in the Ardennes Mountains of Belgium. One side of the quartz cabinet matrix has four pods of lustrous, yellowish-brown ardennite lathes and microcrystals. The large central pod is 4.0 cm long. The other sides of the quartz matrix have smears and crusts of ardennite. This is extremely rich and showy material. Very seldom available in this richness and quality from the Type Locality.