What a romantic ring!  This is a truly stunning vintage (likely early 1900s) 15ct gold, double heart ring, featuring two hearts (the union of two lovers)  and ivy leaves (cling to thee) in two tone; yellow and rose, 15ct Gold.
 
The ring is currently a UK size Q, which is a 8 1/2, and it weighs 4.03g.   It is marked on the underside of its face for the Montana Gold Mine, the mine in which the gold was derived.  The band is no longer hallmarked, probably due to a re-size at some point in its life. 

Please have a look at the photos and video, and dont hesitate to get in touch if you require any further information.