Quartz, a silicon dioxide mineral, is uncommon at both Franklin and Sterling Hill. Although found abundantly in the microcline pegmatites which cut the orebody at Franklin and occurring in moderate amounts in the local rocks, especially in the gneisses, quartz is generally quite rare in the orebodies, even in silicate assemblages which are devoid of ore. Large masses up to 30 cm are known but rare. Superb, prismatic quartz crystals are also found in this assemblage. Fine crystals were reported and illustrated from vugs in the Buckwheat Dolomite by Peters et al.
Massive material is found associated with the notable bannisterite assemblage.
Quartz occurs less commonly with massive rhodonite.