An early 20th century natural pearl and diamond brooch

An early 20th century natural pearl and diamond brooch
The bouton-shaped natural pearl of grey tint to an old brilliant-cut diamond surround between old brilliant-cut diamond five-stone shoulders, circa 1910, 6.5cm long
Accompanied by report no. 08453, from The Gem & Pearl Laboratory, dated 3rd September 2013, stating that the natural saltwater pearl showed no evidence of treatment.