The encrustation is powdery when scratched - although not in all cases, ancient encrustation on pottery flakes and chips but combined with the other characteristics it becomes blatantly obvious.

• 表皮在搽拭时会掉粉尘（灰），尽管有少部分不会发生这种情况，这和彩陶表皮的特征是完全不一样的，所以一眼就能识别。