Iris
Eventually werner founded a research company: Von Croy Industries, which had a towerblock base in New York City. The Iris was taken there for research on it's powers. Lara broke into the tower and stole the Iris sucessfully. She keeps the Iris in her treasure vault to this day.
The Iris appears to be a central sphere of an orange substance that emenates light. Three spherical cups of different sizes rotate at randon patterns around the centre as shown in the image.
Powers
We only see the powers of this artefact in Tomb Raider Chronicles. When Lara is escaping from Von Croy Industries, she uses the Iris to teleport herself to another room. However for this power to be manipulated, a special machine needs to present in both the room where you are being teleported, and the room you are being teleported to. These radioactive machines were constructed by Von Croy Industries.
Appearences
The Iris is the artefact that appears most in the Tomb Raider series. It appears in Lara's treasure vault in Tomb Raider III. The story of how the Iris was obtained is revealed in Tomb Raider The Last Revelation, and the story of how Lara stole the Iris from Von Croy Industries is told in Tomb Raider Chronicles.