Really fine Georgian Specimen Agate  Riviere With Detachable Maltese Cross pendant Circa 1820
Presented In Original Red Morocco Box.
A real collector’s piece!! 
Set in the restrained gold cut down collet style of the period.
Twenty two almost flat stones, so subtly curved, so fine and light; with a larger central stone, chosen because it appears to depict a landscape and sky; flanked by ten pairs of well matched stones, each pair showcasing a slightly different colourway; and a final rust and green agate clasp at the centre back, the stones graduating gently from front to back.
The central stone has a concealed bail fitting that vcan be folded down to add the cross.
The Maltese cross is created from four triangular slices of a banded translucent agate, with a cabochon centre, and the gold wavy tail fitting at the back allows for the cross to be romoved from the collar and used on, perhaps, a long gold chain. 
 
cross measures - 42mm x 42mm
weighs - 7.3g
collar wearable length - 17" 
weighs - 31g
22 agates 
English circa 1820
Front rectangle - 19.5mm x 24mm
High carat gold setting 
Condition - Immaculate