Reddle, Raddle, or Rud-dlE, a species of marle, found in various parts of Britain, particularly in the counties of Stafford and Derby.

This mineral is of a deep-red colour; and, on being handled, stains the ringers. It consists of clay and oxyd of iron ; falls to powder in water ; and, when heated in the lire, becomes black.

Reddle is used in the manufacture of colours ; in the marking of sheep; and, we understand, has lately been employed in Staffordshire, with great advantage, as a manure.