Precious gemstones are rare, valuable minerals that are often cut and polished for use in jewelry. Common examples include diamonds, rubies, sapphires, and emeralds. These stones are prized for their beauty, durability, and rarity, making them highly sought after in the market. The value of a gemstone is determined by factors such as its color, clarity, cut, and carat weight, often referred to as the "Four Cs." Gemstones can also have cultural significance, with some believed to bring good luck or possess healing properties, enhancing their appeal beyond mere aesthetics.