Wad is not a mineral, but an ancient mining term used for Mn ores. There are at least 20 more English synonyms and 15 German synonyms for wad. Wad is a common and important ore of Mn and in some cases contains other elements such as Co.

The term is very useful to name black, bluish-black or brownish-black, dull to earthy masses, formed by submicroscopic, cryptocrystalline crystals of Mn oxides and hydroxides, which are difficult to identify. Mineralogical identification is usually not necessary or imperative, it is sufficient to determine the total Mn oxide content of the wad.

The minerals that form the wad have low crystallinity, are soft and contain significant amounts of oxides and hydroxides of other metals, as well as adsorbed metals such as Ni, Co, Cu, Fe and others.

Their trace can be black, bluish black, brownish black, reddish brown or liver brown. Hardness varies widely, between 1 and 6 on the Mohs scale. The density also varies widely, between 2.8 and 4.4 g/cm³.

There are 7 varieties of wad: with Co, Cu, Fe, Li, Al, Ag and Pb.

Non-Mn minerals associated with wad are secondary Cu minerals (malachite, azurite, cuprite, chrysocolla, duftite), Fe minerals (hematite, goethite, limonite), calcite and wulfenite.