Check the listing for details. 10g glass button made of metals, extremely smooth & shiny, high-tech material. Condition: New. Listed at 35.00 USD. Metallic glass button (no crystal grains inside!), copper alloy, extremely smooth and reflective natural (unpolished) surface, near spherical cap, modern sci-fi style decor and collectible, science gift, educational material. Condition is "New". Mass: 10 grams. Base diameter: ~1.4 cm (0.55 inch). Height: ~ 1 cm (0.39 inch). Other mass is also available at same price per gram - contact seller. Diameter and height approximately scale as cube root of mass. Traditional metals and alloys have numerous crystal grains and crystal defects inside as well as on the surface. Metallic glasses have none. Atoms in a metallic glass are disordered, similar to what's in a liquid or a glass. The shape of a metallic glass is inherited directly from its melt before freezing into a solid. That makes its natural surface as smooth and shiny as a liquid metal, better than any polished surface. Metallic glasses are ~2 to 4 times stronger than traditional metals/alloys (e.g. steels) and ~10 times tougher than oxide glasses. They are really hard to break! Besides their beautiful look, there are a lot of other interesting facts and science topics about glassy alloys.