Since I did not check baggage, I almost had to leave it behind in Xi'an because of its bladelike shape. I then explained to an official at the immigration counter that it's a bookmark I bought from a souvenir shop and I love it so much. Finally a young official (man) seemed to understand an old lady and allowed me to carry this bookmark with me on the plane.
It has already been used once when I read Thai novel about Chinese Dress (Chi-p'ao or Qipao in Thai; Cheongsam in English).