Wad (mineral)

Wad is an old mining term for any black manganese oxide or hydroxide mineral-rich rock in the oxidized zone of various ore deposits.

Typically closely associated with various iron oxides.

Specific mineral varieties include pyrolusite, lithiophorite, nsutite, takanelite and vernadite.

[1] Wad can be considered to be the manganese equivalent to the iron mineraloid limonite.