What, according to the astrologer, was Ranga’s cause of worry? How did the name Ratna crop up?

According to the astrologer the cause of Ranga’s worry was a girl. She probably had the name of something found in the ocean. When asked if it could be Kamla the astrologer did not rule out the possibility. When suggested if it could be Pachchi, the moss, the astrologer put a counter question. “Why not Pearl or Ratna the precious stone ?” Thus the name Ratna cropped up.