This defernite is from the Kombat Mine (Klein Otavi:Asis) in the Kombat, Grootfontein Region, Otjozondjupa Region, Namibia. This locale was discovered in 1850 and mining for the recovery of copper and lead minerals began in 1900. It was closed in 2008 due to flooding. It contained 125 different minerals including defernite. It is a carbonate that contains the elements Ca, C, O Si, Cl and H.This piece consists of a massive hausmanite matrix with streak-like deposits of the reddish mineral defernite. It measures 2 5/8 x 1 7/16 x 1 3/8 inches or 67 x 37 x 35 mm.