Group 1 - The core distinction between gold and red gold is that gold is a single precious metal, while red gold encompasses various gold-colored metals, which may or may not contain gold [6][8] - Gold is known for its stable investment value and is primarily used in high-end jewelry, whereas red gold is often used in everyday accessories and its value depends on the specific composition [8][10] - Consumers seeking investment value should opt for gold items with clear purity markings, while those interested in color variety may prefer red gold, but should be cautious of low-value metals marketed as red gold [10] Group 2 - Gold has been utilized by humans since 3000 BC and is characterized by its bright yellow color and excellent malleability, requiring alloying with other metals for jewelry production [3] - Red gold can refer to high gold content alloys, such as 18K gold (75% gold and 25% other metals), or entirely copper products treated to appear red, showcasing a wide range of color options [6] - The market for jewelry reflects a blend of aesthetic appeal and investment potential, with gold symbolizing wealth and eternity, while red gold offers diverse color expressions [10]