Differential weathering: By the definition from the Random House Unabridged Dictionary, differential weathering is the difference in degree of discoloration, disintegration, etc., of rocks of different kinds exposed to the same environment. Here we define it as the different deterioration of the surface of the traces of carving on jade artifact due to humidity, heat and chemicals in the air after a long period of time. Wrinkles are seen in the traces of carving due to differential weathering.