The birthstones for October are Opal and Tourmaline.
Opals
We also often think of opals as only being white, but like pearls, they also come in a variety of beautiful colours. They are a delicate stone, and are best suited for earrings and pendant, however people do wear them in rings. Special consideration to the design of the ring is needed, and the wearer should be considerate of how they treat their ring.
Tourmaline
Tourmaline is a durable stone and a great choice for rings. It is available in a variety of colours, but the traditional choice of colour for an October tourmaline is pink.