The precious stone traditionally given on a 40th wedding anniversary is the ruby. Known for its vibrant red color, rubies symbolize love, passion, and devotion, making them a fitting gift to celebrate four decades of marriage. This gemstone is also one of the four traditional precious stones, alongside diamonds, sapphires, and emeralds. Rubies are highly valued not only for their beauty but also for their hardness and durability, ranking just below diamonds on the Mohs scale. Gifting rubies on a 40th anniversary is a meaningful way to honor a lasting and loving relationship filled with deep emotional connections.