The phoenix is a legendary male bird with gold and red feathers which has the power of immortality. Legend has it that it lives in the desert, but its life has to be renewed every 500 years. When each end beckons, it's said to make its own nest, a bit like a funeral pyre, with cinnamon twigs and sit on it and consumes itself with fire. When the old body was burnt to ashes, a new egg would be laid and the phoenix is reborn. The phoenix also has the capability of rejuvenating itself when hurt or wounded, making it invincible. The notion of the phoenix is recognised in mythology by various cultures, including Chinese, Greek and Egyptian.
As a symbol, the phoenix represents immortality, resurrection and triumph rising up over adversity. Something with a picture of a phoenix on, such as jewellery, would be appropriate for someone who's overcome a difficult time and is getting on with their life.