Two large, sharp, very glassy, intergrown, doubly terminated Herkimer Diamond quartz crystals highlighted by an interesting plate of gray dolomite rhombs from the less well-known Benchmark Quarry in St. Johnsville, New York. The myriad of internal crazing and rainbow refractions add real character to this striking piece. The terminations are very sharp. This is an excellent quartz-with-dolomite specimen from this locale from the Ed David Collection. Classic material.