Publication:
Phase transformation of epigenetic iron staining: Indication of low-temperature heat treatment in Mozambique ruby

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Issued Date

2016

Resource Type

Article

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application/pdf

ISSN

13554565

DOI

10.15506/JoG.2016.35.2.156

Other identifier(s)

2-s2.0-85006340266

Rights Holder(s)

Scopus

Bibliographic Citation

Journal of Gemmology. Vol 35, No.2 (2016), p.156-161

Suggested Citation

Sripoonjan T., Wanthanachaisaeng B., Leelawatanasuk T. Phase transformation of epigenetic iron staining: Indication of low-temperature heat treatment in Mozambique ruby. Journal of Gemmology. Vol 35, No.2 (2016), p.156-161. doi:10.15506/JoG.2016.35.2.156 Retrieved from: https://hdl.handle.net/20.500.14740/5920

Title

Phase transformation of epigenetic iron staining: Indication of low-temperature heat treatment in Mozambique ruby

Author(s)

Sripoonjan T.
 Wanthanachaisaeng B.
 Leelawatanasuk T.

Abstract

In the past several years, Mozambique has emerged as one of the world's most important sources of ruby, and unheated stones from this country are in particularly strong demand. Nevertheless, it is common for these rubies to undergo low-temperature heating (~1,000°C or below) to slightly improve their colour. The treated stones may show very subtle or no alteration of internal features (e.g. mineral inclusions, 'fingerprints', needles, 'silk', etc.). However, 'iron-stained' surface-reaching fractures in the rubies commonly display a noticeably more intense colour after heating. Raman and FTIR spectroscopy were used to document a transition from goethite to hematite within stained fractures in samples heated to 500°C and 600°C. The identification of hematite within such fractures provides key evidence for the low-temperature heat treatment of Mozambique ruby. © 2016 The Gemmological Association of Great Britain.

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URI

https://hdl.handle.net/20.500.14740/5920

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Scopus: Year 1983-2021

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