The name Opal comes from Sanscrit, upala, meaning precious jewel. They are unusual gemstones of various colours, which change appearance depending on how the light strikes them.
Opals are actually made from silica gel, with water in it. As a result, opals look best when they are worn often, near the skin, where they absorb moisture from the wearer. Place opals in a box for too long and they dry and develop fissures.
The most common opals are white with flecks of rainbow in them. The rarest opals are the fire-opals, which are black with brilliant splshes of yellow, red, blue and green in them.
Most Opals come from Australia, and they are said to soothe the spirit, making a beautiful and serene birthstone for October.