Brown manganese coated. Well developed nodules about 20% with rock centers. Remainder are thinly coated with manganese and have no, or few, nobby incrustations. 70% igneous, 10% metamorphic, 15% sedimentary, mn nodules.
Cite the IMLGS database as: Curators of Marine and Lacustrine Geological Samples Consortium. The Index to Marine and Lacustrine Geological Samples (IMLGS). National Geophysical Data Center, NOAA. doi:10.7289/V5H41PB8 [date of access].