Review on 🍶 Marble-Style Ceramic Coasters with Cork Base - Set of 6: Absorbent Drink Coasters, Ideal Housewarming Gift for Home and Kitchen by Christopher Wiggins

I identify that as absorbent in the description. Unfortunately, this simply means that they stain permanently and very quickly and you cannot remove these stains. I had a friend put a cup of ice on one of them and we couldn't remove the brown circle even by soaking and cleaning with bleach, the other was coffee stained. Cola also colors. Just that tiny bit that runs down the rim of your glass. Now I only have two left that I don't want to use with anything other than water glasses. They are beautiful to look at, but completely useless as coasters.