A really unusual twist on the Victorian diamond arrow brooch, this one with a darling diamond crab, his shell a natural pearl, his eyes sapphires and his claws holding a yellow diamond. 
The trident arrow is set with diamonds, rubies and an emerald.
This can be made into a pendant
The style of this looks circa 1880, however after researching a little, if this was made in 1900 - 1901 then it would celebrate Neptune moving into cancer in the heavens from 1901/2 (and staying for 14 years) 
An event that only happens every 146 years. 
In immaculate condition 
78mm long 
Weight - 14.2g 
High carat gold