This classic and historic New York piece is from the Sterling Iron Mine at Antwerp. Foliated, two-toned gray plates of bladed stilpnomelane are set in matrix. Stilpnomelane is an uncommon layered silicate, and this is a very highly representative, old-time specimen. This old mine closed in 1910. Accompanied by an expertly handwritten, faded label from an older collection. The collection this came out of was a museum stash dating to prior to World War I.