A fine Datolite specimen from a long gone Historic locality, the Bergen Hill tunnel. One of the old labels with this is handwritten and SIGNED by George Kunz, the famed mineralogist Kunz sold many minerals and built three major collections during his career but signed Kunz labels are very rare. This specimen is from the "old tunnel" in Bergen Hill, built in 1857-60. This would have been collected during that construction. A later tunnel in 1881 was dug nearby, both were important localities during the construction but not since. Specimens are now only seen in very old collections, yet this was a significant early US source of Traprock minerals. The Datolites are tiny, very lustrous sparkling crystals some of which seem to have coated earlier Pectolites. There are still numerous Pectolite crystals present especially on the backside. The Datolite seems to be formed in two different generations, most of the crystals are colorless but there is a very faint hint of color in person. Documented specimens from the "Old Tunnel" are very rare on the market.