Four giant hourglasses- One for each house- stand in niches in the corner behind the staff table in the Great Hall. Each hourglass is filled with gemstones rather than sand, one gemstone in the lower bulb for each house point currently held by that House. Gryffindor's contains rubies, Ravenclaw's sapphires, and Slytherin's emeralds. Presumable Hufflepuff's hourglass contains some sort of yellow gemstone.
