This is really quite charming!
A 15 carat gold shield, simply set with a rich plummy garnet in a star cut setting.
Shields have been used as a symbol of protection since ancient times. 
A great piece to wear on it’s own or with a cluster of other charms 
Weighs 1.8g
Measures - 19mm x 14mm not including bail. 
Garnet approx 5mm x 5mm
English circa 1890
Excellent condition