Iris
Eventually Werner founded a research company: Von Croy Industries, which had a tower block base in New York City. The Iris was taken there for research on its powers. In 1997 Lara broke into the tower and stole the Iris successfully. She keeps the Iris in her treasure vault to this day. The Iris appears to be a central sphere of an orange substance that emanates light, somewhat resembling the internal structure of the planet Earth. Three spherical cups of different sizes rotate at random patterns around the centre as shown in the image.
The Iris stored in a security device on The 13th Floor in Von Croy Industires, New York City
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 as a power source 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. The Iris ignores gravity and can hover in mid air.
Appearances
The Iris is the artefact that appears most in the Tomb Raider series. It appears in Lara's treasure vault in Tomb Raider III (implying that she stole it from Von Croy, before the story of Tomb Raider III takes place). 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.