Averages are for Corvallis Municipal, which is 5 miles from Corvallis.
Warnings. Do not use pumice stones to clean marble, laminate, plastic or fiberglass toilets; doing so will result in permanent scratches. A dry pumice stone will also scratch porcelain, so be sure to keep the stone and the toilet surface wet at all times.lean With a Pumice Stone. Before cleaning a porcelain toilet with a pumice stone, you must thoroughly wet both the stone and the surface to be cleaned and keep the stone and the surface wet as you work.
What mineral can scratch a piece of glass â Wiki Answers. Any mineral with roughly a hardness of 6 or more on the Mohs scale of mineral hardness could scratch glass, which is â¦ Some minerals that could scratch glass would be quartz, topaz, corundum, and diamond. â¦ Any type of feldspar or quartz. Â»More detailed.