First Discovery Of Rare Jade In Caribbean Islands Reported By American Museum Of Natural History Scientist

by AMNH on


jadeite jade ax heads found in Antigua

Credit: American Museum of Natural History

An American Museum of Natural History geologist and his colleagues have reported the first discovery in the Caribbean Islands of a rare type of jade, called jadeite jade, known primarily from sources in Guatemala and Myanmar (Burma). The jade was found in the form of ten mottled, dark-green ornamental axes, or celts, excavated from an archaeological dig site on the island of Antigua in the West Indies, dating to about 250 to 500 A.D. The new finding is described in the peer-reviewed journal The Canadian Mineralogist by George E. Harlow, Curator in the Museum's Division of Physical Sciences, and his colleagues A. Reg Murphy of the Museum of Antigua and Barbuda, David J. Hozjan at Overburden Drilling Management Ltd. (Nepean, Ontario, Canada), and Christy N. de Mille and Alfred A. Levinson, both of the University of Calgary.

Previously, there were no documented reports of jadeite jade from the Eastern Caribbean, and there have been only anecdotal or unverified reports of sources of this rock in Cuba, Hispaniola, and Puerto Rico. The minerals contained in the jade of the newly discovered axes closely match minerals found in jadeite rock from Guatemala, suggesting that the axes, or at least the jade from which they are fashioned, originated there and then made their way to Antigua as the result of trade among early settlers (called the Saladoid) of the Eastern Caribbean Islands. This finding is significant geologically and archaeologically as it argues for the primacy of Guatemala as the New World source of jadeite jade and refutes an assertion that all exotic gems and minerals in the Eastern Caribbean were sourced from South America, as no jadeite rock is known from this continent. The finding also has important anthropological implications--it suggests that settlers of this area traded across much greater distances than scholars had previously thought, and it represents the first documented evidence of contact between Central America and the Eastern Caribbean Islands in the early part of the first millennium A.D.



jadeite jade ax heads found in Antigua

Credit: American Museum of Natural History

The term jade is used commonly to refer to either of two tough rocks--jadeite jade and nephrite jade--composed essentially from a single mineral and often fashioned into ornamental carvings and gems that were traded, worshipped, and worn, the former especially by the Maya and Olmec people. Many nephrite jade sources exist, but the prominent archaeological and commercial sources are China, New Zealand, Russia, and Canada. Jadeite jade, far more rare and sometimes referred to as New World jade, as geologists first identified it in artifacts from the Americas, is an extremely hard, durable, and beautiful stone, venerated in jewelry, costume, and burial customs by peoples living in what is now Central America and Mexico over a span of two millennia prior to the arrival of European colonists. Dr. Harlow's published research argues that all Central American and Mexican jade, whether of the Maya, Olmec, Aztec, or others, came from sources in Guatemala. Dr. Harlow led a team of scientists that described new regions with jadeite jade sources in Guatemala. 

In geologic terms, jadeite jade is a rock called jadeitite, and based on details of mineralogy and geology, two types of jadeitite can be distinguished in Guatemala, making matters a bit confusing. Jadeitite found north of a San Andreas-like fault, called the Motagua, in Guatemala differs from that found south of the fault. Although jadeite jade is primarily composed of the mineral jadeite, subsidiary minerals can be used to distinguish the two types of Guatemalan jade from one another and from jadeite jade from all other known sources worldwide. Jade from north of the Motagua fault typically contains albite, analcime, and white mica, but never quartz, lawsonite, or pumpellyite. Jadeite rock from south of the fault can contain the same minerals as those from the north but usually contains quartz and sometimes lawsonite or pumpellyite. Dr. Harlow and his colleagues used these mineralogical differences to argue a jade source south of the fault for the Antigua jades. Their analysis of the polished surfaces on six fragments of the Antigua jade axes included imaging and petrography, scanning-electron microscopy, X-ray diffraction, and electron microprobe chemical analysis. The results demonstrate that the mineralogy, mineral compositions, and rock textures of the newly discovered axes more closely match that of jadeitite from Guatemala, in particular that found south of the Motagua fault, than they do that of jadeitite from Myanmar, Japan, Kazakhstan, Russia, and even relatively nearby Baja, California

The discovery of the Antigua jadeite jade objects, which appear to be ornamental objects rather than tools, suggests that the Saladoid settlers were even more mobile and ocean-faring than previously thought. Anthropologists already had evidence that the Saladoid traveled regularly between islands of the Eastern Caribbean to trade goods and raw materials, but the jade celts and their likely origin in Guatemala suggest that the Saladoid traveled up to 1,800 miles by sea to conduct trade. Some anthropologists presumed that all exotic gems of the Saladoid, like the people themselves, originated in South America. But until now, no geologic analysis was done on these artifacts to back up that idea. This new research on the Antigua jadeite jade objects forces a change in thinking about not only Guatemala but also other mainland locations as possible sites of Saladoid exploration, trade, and exchange. 

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