According to Egyptologist Nicholas Reeves, the mask is "not only the quintessential image from Tutankhamun's tomb, it is perhaps the best-known object from ancient Egypt itself." Since 2001, research has suggested that it may originally have been intended for Queen Neferneferuaten; her royal name (Ankhkheperure) was found in a partly erased cartouche on the inside of the mask.
The mask is 54 cm (21 in) tall, 39.3 cm (15.5 in) wide and 49 cm (19 in) deep. It is fashioned from two layers of high-karat gold, varying from 1.5–3 mm (0.059–0.118 in) in thickness, and weighing 10.23 kg (22.6 lb). X-ray crystallography has revealed that the mask contains two alloys of gold: a lighter 18.4 karat shade for the face and neck, and 22.5 karat gold for the rest of the mask.
The face represents the pharaoh's standard image, and the same image was found by excavators elsewhere in the tomb, in particular in the guardian statues. He wears a nemes headcloth, topped by the royal insignia of a cobra (Wadjet) and vulture (Nekhbet), symbolising Tutankhamun's rule of both Lower Egypt and Upper Egypt respectively. The ears are pierced to hold earrings, a feature that appears to have been reserved for queens and children in almost all surviving ancient Egyptian works of art.
It contains inlays of coloured glass and gemstones, including lapis lazuli (the eye surrounds and eyebrows), quartz (the eyes), obsidian (the pupils), carnelian, feldspar, turquoise, amazonite, faience and other stones (as inlays of the broad collar).
In December 1925, the mask was removed from the tomb, placed in a crate and transported 635 kilometres (395 mi) to the Egyptian Museum in Cairo, where it remains on public display. According to wikipedia.