gyprock

Rock rich in gypsum; gypsic soil.

Some high quality white or variously tinted fine-grained gyprocks, usually referred to as alabaster, were used as interior facing stones and for small statues and carved decorative objects found in Egyptian pyramids

The world distribution of gyprock outcrops and the solubility of gypsum restrict the extensive occurrence of gypsic soils to the dry regions

Drywall.

Cinder blocks were more durable, however, and soon gypsum was redirected for “gyprock” drywall, a wallboard...

To drywall.