It is used in bathrooms a lot and it is very old. Chalk - Formed from the skeletons of time sea animals that are too small to see with the naked eye. Limestone was formed by broken shells and tiny sea cretures. It is solid white color with no other colors. It might look a little chalky.
Diamonds are the hardest known mineral.
Quartzite was formed by sandstone in great pressure and heat. It was slowly cooled and has a whitish crystal. Opal comes from the Romans. It is different colors. Turquois came from the aztecs 3,000 years ago.