Vintage opal and diamond ring

A vintage 18 carat gold ring with a cabochon opal in a halo of 14 brilliant cut diamonds and two baguette cut diamonds. The ring is hallmarked for the City of Birmingham and the year 1978. 

The opal measures 10 mm X 8 mm and is around a 1.60 carat stone. The diamonds are around .20 carat in total, SI1 in quality and H in color. The ring weighs 4.2 grams. 

The ring size is 17.75 mm, the size can be modified if necessary. 

The ring is in good condition. The opal is a lively stone which is mainly red to blue in color.