Crystalline solids are materials whose atoms are arranged in a highly ordered, repeating pattern. This regular structure gives them distinct geometric shapes and well-defined edges. Common examples of crystalline solids include table salt and diamonds, which exhibit unique properties based on their specific arrangements. These solids typically have sharp melting points, meaning they change from solid to liquid at a specific temperature. The orderly arrangement of atoms also contributes to their mechanical strength and optical properties, making them important in various applications, from electronics to jewelry.