September's birthstone is Sapphire.
Sapphires, while most famously known for their deep blue color, actually come in a variety of colors, including pink, yellow, green, and orange. The only color a sapphire doesn't come in is red; red corundum is classified as a ruby instead. Sapphires are a variety of the mineral corundum, making them incredibly durable and perfect for everyday wear in jewelry. This makes them a popular choice for engagement rings and other treasured pieces.