Simply known as Living Stones to many, they are also called Lithops. Lithops are actually succulents native of Southern Africa. Their name is deprived from an Ancient Greek word λίθος (lithos), which means "stone" and "face".
True to form they literally resemble little stones and pebbles in the wild, partly as a camouflage to prevent being eaten by other animals. Each Lithop consists of a part of fused leaves that is separated in the middle. In spring, they produce a pair of new leaves that sprout from the middle of the plant. The new pair of leaves slowly grows out while the old ones start to dry up. When the new pair of leaves are fully formed, usually in Autumn, Lithops produce daisy-like flowers that are often sweetly-scented.
Lithops come in many colors and are truly unique. Colours range from deep red to purple, to pale green. Care for Lithops are relatively simply. Watering-wise, less is more. When they are producing new leaves, it is recommended to completely stop watering until the new leaves are fully formed, and the olds have shrank and dried up. During this period, the plant actually takes it's nutrients from the old leaves.
Water about once a month, or when the edges of the plant starts to wrinkle alittle. Be careful not to water on the plant. One tablespoon around the plant is sufficent. Allow the excess water to drain before setting the plant at its orignal location. Place in a bright sunny environment with good air circulation.