Thickness: 0.7mm/0.027" Pendant Size: 3.6*2.1CM(1.44*0.84INCH) Hook: Single Hook Chain type: Bead Chain Material: 925 Silver Thickness: 0.7mm/0.027" Pendant Size: 3.6*2.1CM(1.44*0.84INCH) Hook: Single Hook Chain type: Bead Chain Material: 925 Silver Double Heart Necklace with Name & Birthstones Sterling Silver - The personalised heart necklace is the perfect gift for couples!Pendant is personalised with his and her names and faceted birthstones.It shows the world how beloved your loved one is to you and take personalization to a whole new level. When you sleep, your body produces a lot of sweat and gives off a lot of heat, both of which can cause serious damage to jewellery. Sweat can cause it to tarnish or rust, while the heat can cause soft metals to deform.