Rare vintage orange natural abalone shell rectangle beads. 19x8x5mm. 15 inch strand. b15-aba412

Vintage natural polished orange abalone shell rectangle beads.  These  beads have the matte orange shell on 1 side and on the other side iridescent rainbow  colors.  The color is completely natural.  These beads have become extremely rare.   They were plentiful mid 20th century but are no longer available.  The vintage and antique abalone shell jewelry was often made from this type of abalone.    The beads average 19x8x5mm.  15 inch strand.  Several of these strands have a MADE IN JAPAN label on them.