This is an antique gold sapphire stick pin. This stick pin features a single round blue sapphire set in a star mount on a 15ct gold oval etruscan style head.  It measures approx. 5.5cm tall and weighs 1.6g. 
Dimensions: 57mm x 8mm x 6mm
Sapphire: 1 x 0.03ct
Marked: '15ct'