All minerals have a certain hardness. The hardness of a mineral is determined by performing a scratch test. A scratch test is based on the Moh’s scale of hardness. A German scientist invented this scale by taking several known, pure minerals... Read More

Q. I hired a cleaner and she used a limescale remover with mold control. It appears to have left white stains on my bathroom stone tiles. These don’t wash away with water. What should I do? A. What you’re seeing is likely etching, not... Read More

Q. I have a Pietra Cardosa countertop. I was using a descaling chemical solution to clean an appliance and accidentally spilled some, leaving a handprint-sized discoloration. The black countertop has turned almost white in that area. If you have any... Read More

Q: Hi. I have applied a poultice of DE and iron out to white marble to try to remove the iron. Where do you purchase a chelating agent that is to follow? A:  If the iron out works than a chealting agent would not be needed. For those unfamiliar... Read More

Granite is much harder than marble. The hardness of stone is measured on a scale of 1 to 10. Ten is the hardest mineral. Diamond is a ten. Most marbles fall in the 3-5 range and granites fall into the 7-8 range. A simple test to determine if you are... Read More

Q. Water feature has chlorine residue buildup causing a white stain on natural rock waterfall. How can I remove the chlorine residue from the rock? A. What you are seeing is likely mineral deposits. Chlorinated water doesn’t cause the deposits,... Read More

Q. I just finished putting in a new black marble shower wall... literally giving it its first cleaning. I had no idea that some bathroom cleaners would immediately etch into it. Please, for the love of God, tell me there’s something I can do...... Read More