Oxygen isotopes and emerald trade routes since antiquity

Science

Volumn 287, Issue 5453, 2000, Pages 631-633

  Giuliani, Gaston ^a,b   Chaussidon, Marc ^b   Schubnel, Henri Jean ^c   Piat, Daniel H ^d   Rollion Bard, Claire ^b   France Lanord, Christian ^b   Giard, Didier ^d   De Narvaez, Daniel ^e   Rondeau, Benjamin ^c  

^a INSTITUT DE RECHERCHE POUR LE DÉVELOPPEMENT   (France)

^b CRPG CNRS   (France)

^c MUSÉUM NATIONAL D'HISTOIRE NATURELLE   (France)

^d Assoc Francaise de Gemmologie   (France)

^e Compania Mineira Rio Dulce ^*  (Colombia)

Author keywords

[No Author keywords available]

Indexed keywords

ALLOY; METAL; NIOBIUM; SILICON;

EMERALD; ISOTOPIC COMPOSITION; OXYGEN; PROVENANCE;

ARTICLE; CONDUCTANCE; DYNAMICS; MEASUREMENT; PHASE TRANSITION; PRIORITY JOURNAL; QUANTUM MECHANICS; TEMPERATURE;

EID: 0034723242     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.287.5453.631     Document Type: Article

References (21)

1. F. Ward, Emeralds (Gem Book Publishers, Bethesda, MD, 1993).
2. E. Gonthier, in L'émeraude, G. Giard, G. Giuliani, A. Cheilletz, E. Fritch, E. Gonthier, Eds. (Association Française de Gemmologie Press, Paris, 1998), pp. 27-32.
3. F. H. Forestier and D. H. Piat, in L'émeraude, G. Giard, G. Giuliani, A. Cheilletz, E. Fritch, E. Gonthier, Eds. (Association Française de Gemmologie Press, Paris, 1998), pp. 139-145. Indian traders use the terms old mine emeralds or Moghul emeralds to designate emeralds of exceptional color, carat weight, cut, and clarity. These stones were cut in the 17th and 18th centuries A.D., but some of them might originate from older treasures. These emeralds have an unknown origin, but they are classically advocated to come from old mines lost in the past. They are also called "Bactriane" emeralds by historians who think that they were picked up by Alexander the Great in 300 B.C. during his far eastern conquest via the Pansher Valley in Afghanistan.
4. G. Giuliani et al., Miner. Deposita 33, 513 (1998).
5. The Nuestra Señora de Atocha galleon sank on 4 September 1622 off the coast of Florida when ravaged by a hurricane [E. Lyon, Natl.Geogr. 149, 786 (1976)]. In 1985, divers found the Atocha galleon and recovered gold, silver, and 2300 rough emeralds [E. Lyon, Natl. Geogr. 161, 228 (1982)].
6. The Nuestra Señora de Atocha galleon sank on 4 September 1622 off the coast of Florida when ravaged by a hurricane [E. Lyon, Natl.Geogr. 149, 786 (1976)]. In 1985, divers found the Atocha galleon and recovered gold, silver, and 2300 rough emeralds [E. Lyon, Natl. Geogr. 161, 228 (1982)].
7. -11 g of an emerald were sputtered for one analysis). These spots are invisible to the naked eye, so this method can be considered nearly nondestructive and can be applied to gems of high value.
8. 18, in which a minor amount of Cr(V) is present. Two main types of emerald deposits are recognized worldwide (4): Type I, which corresponds to most of the deposits, involves the intrusion of granitic pegmatites within Cr(V)-bearing mafic-ultramafics. Type II emerald forms in thrusts, faults, and shear zones in Cr(V)-bearing rocks.
9. 18O = 21.2 ± 0.5‰).
10. The mineralogical and gemological data that are normally used to determine the origin of natural emeralds are the optical features (refractive indices and birefringence), density, adsorption spectra (ultraviolet and near-infrared), internal characteristics (growth phenomena and solid and fluid inclusions), and the chemical composition. However, the diagnostic value of these data is often restricted, because there may be an overlap for emeralds originating from different localities. On the other hand, the combination of mineralogical and gemological properties can be used, in many cases, to accurately identify emeralds from specific localities. Sometimes, even certain isolated data are highly characteristic. For example, emeralds from the Brazilian deposits of Salininha and Santa Terezinha, as well those from central Nigeria, can be identified by their spectroscopic data.
11. R. Dominguez, in Historia de las esmeraldas de Colombia (Graficas Ducal Edition, Bogotá, Colombia, 1965), pp. 131-159.
12. J. C. H. Zwaan, J. Kanis, E. J. Petsch, Gems Gemol. 33, 80 (1997).
13. D. Schwarz, in Esmeraldas - Inclusões em gemas, D. Schwarz and Universidade Federal Ouro Preto (UFOP), Eds. (Imprensa Universitária UFOP, Ouro Preto Publishers, 1987), pp. 304-305.
14. Y. Y. Nwe and G. Grundmann, Lithos 25, 381 (1990).
15. C. Beurdeley, in Sur les routes de la soie (Edition Seuil, Fribourg, 1985), pp. 14-35.
16. The first Colombian emeralds in Europe were given to Hernán Cortés by the Aztec emperor Moctezuma II. These gifts were given to Charles Quint and were described by Albrecht Dürer in 1520. Some of these great samples, which were traded through Mesoamerica from the 10th century onward, are now curated at Vienna and Dresden (16).
17. P. Bariand and J.-P. Poirot, in Larousse des pierres précieuses (Librairie Larousse, Paris, 1985), pp. 133-142.
18. 2 liquid up to 3 volume %), which is easily visible in flat and large inclusions. These halite-bearing fluid inclusions are commonly used as the main criteria for diagnosis of Colombian emeralds, but they cannot be used to determine the origin more precisely to find the mine locality.
19. R. E. Kane et al., Gems Gemol. 25, 196 (1989).
20. 18O = 20.0 ± 0.8‰ (eight analyses)].
21. We thank the Mel Fisher Maritime Heritage Society in Key West, Florida, for providing a rough crystal from the Nuestra Señora de Atocha galleon. This is contribution CRPG-CNRS no. 1444.