1998 1 Oz Mexican Libertad MS68

This is the key date with an extremely low mintage for a popular bullion series. The coin is difficult to find in any condition, let alone in higher grades.  

Obverse: The Coat of arms of Mexico is shown with a Mexican golden eagle perched on a prickly pear cactus devouring a rattlesnake. This imagery relates to the founding of Tenochtitlan, present-day Mexico City. The coat of arms is rooted in the legend where the god Huitzilopotchli told the Aztec people where to build their city where they saw an eagle eating a snake on top of a cactus. The bottom half of the coat of arms has oak and laurel leaves encircling the eagle. The top half has the words "ESTADOS UNIDOS MEXICANOS" encircling the eagle.

Reverse: The design used was based on the 1921 gold Centenario, a coin issued to mark the centennial of Mexican independence. The winged Victoria of Angel of Independence is in front with the volcanoes Popocatepetl and Iztaccihuatl in the background. The new Libertad series shows a three-quarter side profile of the angel. Inscribed across the top are the denominations "1 ONZA", the composition "PLATA PURA", and "1998 LEY .999", which specify the date and purity. The "O/M" mint mark can be found on the right. The Libertad series is widely regarded as being the most beautiful world bullion series.