Silver

Silver is the 3rd clue. It is an Ekaterina clue and was located in Cairo, Egypt.

History
This clue was given to T.E. Lawrence in order for him to hide it. He hid it in the Rosetta Stone translation book, which was then taken by the Ekats and put in the Cairo stronghold. Napoleon Bonaparte, a Lucian agent, invaded Egypt, trying to get the clue, but failed.

Silver
Silver is an uncommon metal. It is mostly used in jewelry, conductors, and coins.