This is a vintage sparkling rhinestone necklace.  The rhinestones are prong set and show a rainbow of colours in different lights. 

 

The large stones are approximately the size of a 1carat diamond are are brilliant in sparkle.  There are smaller rhinestones to the back of the necklace.  All rhinestons have been set on a gold tone metal. 

 

The tennis necklace measures 17 inches and is adjustable in length.