~US imported brass, lead-free and nickel-free, in line with US and EU standards. ~Why lead-free and nickel-free? https://en.pinkoi.com/store/jadeartjewelry?tab=story ~60s vintage glass. ~No dyeing, glue or welding is involved in the production. ~Colour of each piece of work is unique due to natural oxidation of brass. Your understanding is appreciated. Feel free to contact us before any purchase. ~All piece of work is coated with wax to slow down further oxidation. However, metallic oxidation is a natural process, therefore, we advise customer to store the jewels in bag and jewelry box in dry and cool area. ~Since every piece is unique and handmade, only a small amount is made each time. Please contact before any purchase to ensure there is enough stock.