Vibranium

Vibranium is the name of a rare element.

History
Vibranium comes from a nation called Wakanda, a small country in Africa and is the rarest metal on earth. Vibraniun absorbs vibratory energy in its vicinity, such as sound waves, within itself. The apparent observable vibratory rate of the molecules of the Vibranium itself does not noticeably increase when the Vibranium absorbs mechanical energy. The outside vibratory energy is stored within the bonds between the molecules making up the Vibranium.

Iron Man 2
Tony Stark rediscovered the element after decoding a hidden message containing the structure of the element left in the diorama of the 1974 Stark Expo by his father, Howard. Although unnamed in the film itself, the novelization identifies the element as vibranium. Stark later uses it in an experiment and after charging it with a high power laser (and destroying most of the room) he uses it to prevent the poisoning of his blood.

Captain America: The First Avenger
Captain America's shield was constructed by Howard Stark using vibranium. Howard states that vibranium is stronger than and a third of the weight of steel, is completely vibration-absorbent. It was strong enough to resist several laser projections from the HYDRA's guns, powered by the Tesseract.

The Avengers
Captain America's shield is kept by S.H.I.E.L.D. and displayed with his new suit designed by Agent Coulson. It proves effective against blasts from Loki's staff, a direct hit from Mjölnir, and the legions of Chitauri. It was also able to reflect/bend the Iron Man suit's repulsor beam.

"The Well"
The interrogation room in the Bus is made out of Vibranium.

Captain America: The Winter Soldier
to be added