Scion
It was created by the three leaders of Atlantis, Qualopec, Tihocan and Natla. It was split into three segments to represent to the democratic leadreship that the three used in governing Atlantis. Each of the three rulers was given a piece of the Scion, which they wore around their necks.
Aware of the power contained in the device, Tihocan and Qualopec were wary of its use, but Natla went against them and used the Scion for her own genetic experiments. When the other two discovered Natla's treachery they condemned her to eternal imprisonment and buried her third of the Scion deep within the city of Khamoon, in Egypt.
After the destruction of Atlantis, Tihocan and Qualopec went their separate ways, travelling to different corners of the world. When each ruler died, they were buried along with their piece of the Scion. Qualopec's tomb is deep within a mountain in Peru, and Tihocan was buried beneath a vast structure in Turkey.
Lara recovered all three of the lost pieces of the Scion, but it was then stolen by Natla. She used it to continue her genetic experiments, but Lara destroyed it before it could be used extensively.
The sections now rest safely in Lara's trophy room in her mansion.
Tomb Raider: Anniversary
The Scion will be returning to Tomb Raider: Anniversary in much more detail.
Nothing has been confirmed about it as of yet, but it is expected to have the same powers in the new game, since it resembles an important part of the first Tomb Raider storyline.
Powers
The exact nature of the power of the Scion are unclear. Brother Herbert of St. Francis' Folly described it as possessing "powers beyond the creator himself". It seems that it is essential to Natla's experiments, but exactly why is not explained. It seems that it is the power source for the Great Pyramid, and that the Pyramid itself is the tool for her genetic engineering.
