Removing water stains from furniture. --The white mark is caused by trapped moisture, which is water. It then makes sense that to eliminate it, you need to cause the water to evaporate, and the best way to do is is by directly applying heat. If you do this method properly, the stain will be gone in no time. You can use either a flat iron or a blow dryer.
55 Must-Read Cleaning Tips and Tricks (With Pictures)