Au, or gold, is a shiny, yellow metal known for its rarity and beauty. It is a chemical element with the symbol Au and atomic number 79. Gold is highly valued for its use in jewelry, electronics, and as a form of currency throughout history. Its resistance to tarnish and corrosion makes it ideal for various applications. Gold is often found in nature in its pure form, but it can also be extracted from ores. It is typically measured in troy ounces and traded on global markets. The demand for gold remains strong, driven by its cultural significance and investment potential.