Those silver and gold teacups iare made by a creative and accomplished team called Bian in Jingdezhen (check here to see more about Bian).
Those cups stand out by the extremely thin wall textured with lots of vertical pin-strips throughout , being aesthetically beautiful in form and light to hold. The primary matte black glaze( same with other Bian's black crafts) gives the cup a metallic sheen , and the silver or gold glaze is applied at the lower part on the outside , giving a stunning visual contrast.
Each teacup holds 50ml of liquid up to the rim. The rim is extremely thin which prevents the fingers from the heat and the lightweight character makes it pleasing to hold. Regardless of delicate appearance, the clay used is strong and practical in using without much worry of fragility.