A superb thumbnail cluster of sharp, translucent snowy white harmotome crystals, from Sing Sing, NY. The old label from the Columbia College School of Mines, and the specific dig location, dates this to prior to 1900. The Columbia collection went to the AMNH, and from there it was exchanged into the collection of dealer/collector Lawrence Conklin. It is a superb harmotome no matter where its from, and I cannot recall seeing a better US example of the species either.