Antique Victorian diamond and ruby star set trilogy ring 18 carat gold

Era: Victorian 1837-1901
Metal: 18 carat gold, partial hallmark
Gemstones: old cut diamond 2.5x2.2mm, rubies x2 2.2mm
Size: UK O/US 7.25/EU 55
Weight: 3.8g
 
Nothing better than a star set trilogy! This one features a central bright old cut diamond, accented with two rubies. The shank is 5.6mm wide at the front, tapering to 3mm wide at the back, for comfort. 
 
There is evidence of a past sizing, which unfortunately means the date letter has been lost, but I would date it to the end of the 19th century C.1890-1900.
 
It is in very good antique condition, with just minor signs of wear commensurate with age.