Metals are solid materials that are typically shiny, malleable, and good conductors of heat and electricity. Common metals include iron, copper, and gold. They are used in various applications, from construction to electronics, due to their strength and durability. Gems, or gemstones, are precious or semi-precious stones that are often cut and polished for use in jewelry. Examples include diamonds, rubies, and sapphires. These stones are valued for their beauty, rarity, and hardness, making them popular choices for adornment and investment.