925 sterling silver earrings from the designer Nataliya V. Collister. Hallmark Meanings 925: This is an international standard indicating that the metal is 92.5% pure silver. The remaining 7.5% is typically copper, added to give the silver enough strength and durability for jewelry. NVC: This is the maker's mark for Nataliya V. Collister, a designer based in Kingston, Jamaica. Her brand, sometimes commissioned for companies like Avon.