Note 27 — Front matter

Red Pipestone, a fine grained argillaceous sediment, the analysis of which is as follows: Silica, 48:20, alumina, 28:20, ferric oxide, 5, carbonate of lime, 2:60, manganous oxide, 0:60, magnesia, 6, water 8:40, loss 1. First brought to the attention of mineralogists by George Catlin and named in his honor “catlinite.”