Ko te perlite roha whakarahihia he momo porous, he ma, he mea putorino hei hanga mai i te puia putake o te puia waikawa na roto i te kuru, te whakamahana, te tunu me te whakawhaanui. He iti te kaha, he iti te kawe waiariki, he pai te pumau o te matū, kaore e wera, kaore e ngiha, kaore ano hoki e wera. He paitini, he kakara, he ngongo tangi me etahi atu ahuatanga.