Attractive 1920s Cut Glass Bar Brooch Blue or Turquoise

Original Early 20th Century vintage bar brooch, more than likely 1920s.
Silver tone metal bar with a cut glass imitation blue or turquoise gemstone
in the middle and flanked by a little diamante crystal on each side.
The brooch pin is secured with an innovative safety catch - see last photo.
The whole brooch is just over 7cm long and the glass centre is 1.5cm x 1cm