Housekeeping tips: getting stain off of bone mahjong tiles
I have a lovely mahjong set with tiles made of bone and bamboo, all fitted into drawers that go into a wooden case. The last time it was put away, someone put the tiles into one of the drawers face-down. Yesterday afternoon when I got it out to play, all of the tiles that had been face-down in their stained wooden drawer had picked up an orangish color. It's really ugly.
Question: who has ideas about how to clean off the orange color, without hurting the bone and without removing the designs on the tiles?