low-temperature ruby heat treatment

  • Canary in the Ruby Mine — Low-Temperature Heating of Burmese Ruby

    • Date: 01-01-2023
    A Canary in the Ruby Mine • Low-Temperature Heat Treatment Experiments on Burmese Ruby

    Detection of heat treatment below 1200°C in ruby and sapphire can present challenges to gemologists. In this study, the authors heated Burmese ruby samples and detailed the features that help in the detection of heat treatment.

  • Mozambique Ruby — An Expensive Mistake

    • Date: 10-21-2022
    Mozambique Ruby — An Expensive Mistake

    A 6 ct Mozambique ruby submitted as untreated showed evidence of heat treatment through infrared spectroscopy and microscopic examination. Diagnostic features included a 3232 cm⁻¹ infrared peak, partially broken-down crystals associated with rutile silk, and surface spall marks indicating heating after cutting. The case highlights how treatment can substantially reduce a fine ruby’s value while offering little improvement in appearance.