Water Rings on Marble
I've seen posts where people talk about glasses leaving water rings on their marble countertops (or other marble surfaces). Are those water rings caused by etching and if so why would plain water etch (unless you lived somewhere with slightly acidic water)? Or, are the rings formed by the deposit of the minerals found in hard water? Any reason why the condensation from glass with ice water would leave a ring, but it's still ok to use the same tap water to spray or wipe down your counters? Thanks!