Quartz pseudomorph after barite. Ex Brother Juan Salvador, FMS, a volunteer at the AMNH in the 1880s. His card apparently read One of the great treasures of my collection, 16/7/1884. Ex American Museum of Natural History. Ex British Museum Collection, number 68. Ex Eugene Carmichael Collection, number 266. Specimen has a pasted number of 2139 57. From Jamie Newman: Apparently he (Brother Juan Salvador) helped himself to many many specimens from AMNH, primarily rares. Sometimes folks donate these things back.