Detailed Instructions: Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.
Q: Though it is the most abundant metallic element in Earth's crust, which element is very rare in its free form and once prompted Napoleon III, Emperor of France to give a banquet where the most honoured guests were given utensils made of it while the 'lesser' guests had to make do with gold!?
A:
aluminium