This molecular serotonin necklace celebrates a love of life and scientific pursuit. Crafted from 925 sterling silver and opal it is hypoallergenic anti tarnishing and free of nickel lead and cadmium. Measuring 106 by 084 inches it is ideal for sensitive skin and long term wear. Each necklace comes beautifully presented with a silver cloth and gift box. It makes a perfect gift for chemistry enthusiasts researchers and loved ones like mothers fathers sisters or daughters. Suitable for birthdays graduations Christmas and holidays. We offer dedicated service to resolve any quality concerns promptly and satisfactorily.