Fake turquoises investigated by Raman microscopy

Author(s)

Bernardino, Nathalia D'Elboux ^[1] ; Izumi, Celly M. S. ^[2] ; de Faria, Dalva L. A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Fed Juiz de Fora, Dept Quim, Rua Jose Lourenco Kelmer S-N, BR-36036900 Juiz De Fora, MG - Brazil

• Document type: Journal article
• Source: Forensic Science International; v. 262, p. 196-200, MAY 2016.
• Web of Science Citations: 1

Abstract

Turquoise is frequently adulterated by unscrupulous dealers and, not rarely, simulants are commercialized as true stones. On the other hand, turquoise is a cryptocrystalline mineral and its use in adornments commonly demands some kind of treatment to facilitate its manipulation, such as impregnation using oil or fats, consolidation with resin and stabilization or reconstitution made with resins. In this work, Raman microscopy was employed in the investigation of turquoise adornments aiming to differentiate processed turquoise from fakes or simulants. Only one out of the five adornment objects analyzed was truly stabilized turquoise (powdered turquoise aggregated with a resin). Another one was constituted of turquoise, calcium carbonate, phthalocyanine blue and resin; the other objects were dyed minerals. (C) 2016 Elsevier Ireland Ltd. All rights reserved. (AU)

• FAPESP's process: 12/05643-4 - Impact of nanostructural aspects on the stability of dyes and pigments of archaeological interest
• Grantee: Nathália Delboux Bernardino
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/13119-3 - Vibrational spectroscopy in condensed phases
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants