Rockwool pipe at cheap prices Rockwool pipe bullion products is lightweight economical thermal insulation material that is also recognized as one of the best materials for the purpose of thermal insulation and is made from a mixture of natural stone (basalt and dolomite) melts at high temperature to form a liquid matrix, which is then passed through the air flow cools the material and shape of the long fibrous strands. These strands are bound together to form sheets, duvets, quilts, block pipe and granulates