After a few minutes on Google (that's all the education anyone needs, right?), I found that pearls were used in ancient Mesoamerica. The Handbook to Life in the Ancient Maya World by Lynn V. Foster (Cambridge, Mass.: Oxford University Press US, 2005) tells us that pearls were among the items considered precious enough to be buried with wealthy Mayans (p. 10). When Cortes met Montezuma, the Aztec king was wearing a cloak and sandals that were "sprinkled with pearls and precious stones" (William Hickling Prescott, History of the Conquest of Mexico, A. and W. Galignani and Co., 1844, p. 47).
Thomas Francis Gordon in The History of Ancient Mexico: From the Foundation of that Empire to Its Destruction by the Spaniards (published by the author, 1832) provides a list of some of the gifts Cortes sent to Charles V, where we see pearls prominently and repeatedly mentioned (p. 342-343).
In fact, it turns out that the many varieties of pearls available in ancient Mexico -- as in "all manner of fine pearls" -- were of great interest to Cortes and the leaders of Europe. An article at CortezPearls.com explains:
It is fitting that Mexico's most successful cultured pearl farm ever should be located in the Sea of Cortez. There in 1533, Hernan Cortez, the Spanish conquistador who 13 years earlier had defeated the Aztec nation and claimed Mexico for the Spanish Crown, launched the first of three pearl expeditions--the last, in 1536, led by Cortez himself.
The Spaniard wasn't looking for the white pearls found by the ton off of Venezuela. Nor was he looking for the pretty pink conch pearls of the Caribbean. He was looking for a unique variety of dark gray pearl-many with purple, green and blue overtones-that he had often seen worn by the natives of Mexico.
Cortez had an inspired hunch that Mexico's black pearls would add wide diversity to the then rather limited color spectrum of this gem. Most pearls were white, cream or yellow. Mexican pearls often boasted striking eggplant-purple, sky-blue and peacock-green colors in addition to the pewter-grey or jet-black varieties. Cortez gambled that shipments of black pearls would be just as welcome by his royal sponsors as shipments of white pearls.
[new page] Black pearls have never been found in the quantities of white pearls. Nevertheless, for centuries Mexico was a prodigious supplier of this variety. Cortez, the first Westerner to hunt for black pearls with systematic determination, had two species of pearl oyster to choose from: the Pinctada mazatlanica (La Paz black-lipped pearl oyster) and the smaller but more colorful Ptenia sterna (Western Winged rainbow-lipped pearl oyster). Not only were these mollusks plentiful, they prolifically produced pearls, often as many as 14 out of every 100 shucked oysters.
Because of its oyster plentitude, Mexico was known for nearly four centuries as the world's sole and then later primary source of black pearls-gradually giving way to Tahiti after 1850.
Further north, freshwater pearls were known among ancient Native Americans and many have been found in sites built by the ancient mound builders. See The Mound Builders of Ancient North America by E. Barrie Kavasch, p. 407.
Searching for pearls in ancient Mexico, Google initially led me to the fascinating writings of Zelia Nuttall (Zelia Maria Magdalena Nuttall, 1857-1933). Zelia was an American archaeologist and anthropologist who studied in Europe, managed to learn Nahuatl, and focused on pre-Columbian Mesoamerican manuscripts and the Aztecs and their predecessors. She was made wrote several acclaimed scholarly works, became an honorary assistant of Harvard’s Peabody Museum, and was named honorary professor of the National Museum of Mexico. Not bad in light of the obsidian ceiling for that age. I'll have a few things to say about her writings in a subsequent post. Stay tuned, seerstone fans!