|In 1922 British archaeologist Howard Carter discovered a large breastplate, decorated with gold, silver, various precious jewels and a strange gemstone. Carter identified the gemstone at first as chalcedony, a common variety of quartz. A decade later strange pieces of glass were found in the Libyan Desert along the border of modern Egypt. The pale yellow and translucent material seemed to be identical to the gemstone found in Tutankhamun's tomb.||Libyan Desert glass (LDG), is an impactite with fragments found over areas of tens of square kilometers.|
LDG is almost pure silicon-dioxide, like quartz, but its crystal structure is different. It also contains in traces an unusual combination of elements, like iron, nickel, chromium, cobalt and iridium.
It's thought LDG formed 28 to 26 mya when an impact melted quartz-rich sands of the desert.