Back in 1631 the emperor Shah Jahan built the Taj Mahal for his deceased wife, Mumtaz Mahal, to honor her memory . It is regarded as one of the seven wonders of the world. Sadly this wonder is becoming tarnished by the day. Due to pollution, the Taj Mahal marble is starting to turn yellow. Even though, every couple of years the mausoleum is given a clay mask to remove all the grime and restore the sparkling white marble, the grime returns over and over again every few years.