No country currently backs its currency with gold, but many have in the past, including the U.S.; for half a century beginning in 1879, Americans could trade in $20.67 for an ounce of gold. The country effectively abandoned the gold standard in 1933, and completely severed the link between the dollar and gold in 1971.
Peter Carl Faberge’s first egg for the Russian royals is also called the hen egg and was made of gold and white enamel. The inside of the egg had a yolk made of gold within which was a golden hen. The eyes of the hen were made of rubies. The golden hen concealed a miniature crown and at the centre hung a tiny ruby egg.