I just received a diamond ring from my husband that belonged to a
deceased sister. The centre stone used to be in his mother’s
engagement ring which was purchased in the 1920’s. It was appraised
many years ago as a .39 carat SI 1 graded at I to K colour. His other
sister remembers it as a Bluebird diamond and I am trying to find out
what this means. Is this a certain cut or just a trade name for
manufacturers brand? Thank you.