GIA Verifies Columbian Era Pearls
The present study focuses on a group of pearls reportedly from the pre- to early Columbian era. They were purportedly collected in Central or South America, most likely off the island of Cubagua, although their history and exact origin are not clear. The pearls appeared to be old, judging from their external form and the worn condition of their nacreous surfaces (figure 3). Gemological examination at GIA and age dating at the University of Arizona and the University of Tokyo confirmed that these were saltwater natural pearls from the pre- to early Columbian era. Meanwhile, the Gübelin Gem Lab conducted an independent study on pearls from the same supplier that were said to be from the same geographic source. Their results are included in this joint study in order to identify the nature and origin of these intriguing gems.
The New World’s most productive sources of pearls in the early 1500s were the oyster beds near the Venezuelan islands of Margarita, Cubagua, and Coche, and to a lesser extent in the waters off the Colombian coast and the Gulf of California in Mexico (Mackenzie et al., 2003; Southgate and Lucas, 2011; see figure 1). Within
a few decades of the New World’s discovery, the production of natural pearls peaked as a consequence of heavy demand in the Old World. These treasures were shipped to Spain and used in jewelry and ornamentation for the nobility and the Church. During the Renaissance period, pearls and pearl jewelry became extremely popular in Europe due to the influx of significant quantities of saltwater pearls from the newly discovered Americas (Dirlam et al., 1985). Even today, famous historical pearls such as La Peregrina or the Hanoverian pearls owned by Queen Elizabeth I are still in fine condition. Archival records and auction house sales prove that “old pearls” have survived through the centuries. Yet the Spanish failed to understand the importance of conservation and sustainable harvesting (Romero, 2003). Production fell sharply by the mid-1500s due to the scarcity of oysters and as a result of indigenous rebellions (Romero et al., 1999).
To summarize, both gemological and advanced chemical analyses confirmed that these were natural saltwater pearls, probably from a Pinctada species mollusk—e.g., Pinctada imbricata, which were harvested en masse during the Spanish colonization—if the reported geographic origin of the pearls is accurate.
Read entire article here: https://www.gia.edu/gems-gemology/fall-2017-saltwater-pearls-columbian-era