Nagina Masjid or the Gem Mosque is made up of pure white marble and was meant for the personal use of the emperor. Built between 1631-40 in the northwestern corner of the Machchhi Bhawan, it has a marble paved court enclosed by walls to the north, south and east and the prayer chamber on the west. The prayer chamber is also made up of marble and has three domes on its top. The mosque has a three-arched façade with the cusps and supported on slender piers as its entrance. The arch in the middle is larger and has nine cusps and ones on the either sides have seven cusps only.