The British Gypsum mining processDec 14, 2015 . We're going underground. How Thistle Plaster is made. The process starts by extracting gypsum rock deposits from the ground using a 'JOY mine cutter' that scores away at the face of the gypsum rock. This is then broken up and transported to the surface. It's homogenising time. How Thistle Plaster is made.process for mining gypsum,Knolls Natural Gypsum Mining ProcessSep 12, 2014 . Here I just let the camera roll as we process Knolls Natural Gypsum.