Granite Cuff Fnfzig Jahre Bone Cuff Tiffany & Co. Fnfzig Jahre Bone Cuff Tiffany & Co. Fnfzig Jahre Bone Cuff Tiffany & Co.. Ariana Boussard Reifel granite cuff in brass. 100% Brass Yellow Brass: The high copper content in brass can cause it to darken over time. This is primarily due to a reaction to water and humidity. Some people, depending on their personal PH balance, experience a green coloring to the skin when it comes in contact with brass. This is perfectly safe and is again due to copper, think of it the Stature of Liberty Effect. If you prefer to avoid the dark patina to the metal, try to keep your brass as dry as possible. Don't swim in it and dry it after washing your hands. In humid climates keep the brass in an airtight container or bag with a piece of chalk to absorb moisture. For a bright shine, it is easiest to use a commercial polish like Brasso to restore your piece to its original luster. You can also soak the jewelry in ketchup. The acid in the tomato will help to remove tarnish. Made in the United States