Scholarlink

<p>Color changes of the natural gemstones zircon, andradite, and cassiterite during their heat treatment in various media have been studied. Initially almost black zircons turned pale-yellow after heating at 1100°C under oxidizing conditions (air oxygen); bright blue, at the same temperature under reducing conditions (carbon monoxide). Color reversibility in addition to such contrasting color changes was also noted in andradite, depending on the heat treatment medium. Crystals in a repeated series of experiments at the same temperature (830°C) in air turned light brown; in the presence of a reducing agent, returned to a saturated green color. Thus, the key factor determining the observed color changes was the heating medium.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Role of Heat-treatment Environment in Color Changes of Natural Gemstones Using Zircon, Andradite, and Cassiterite as Examples

  • 期刊论文

  • 发表日期：

    2026年7月6日

查看全文
  • E. A. Akhmetshin,
  • I. A. Klimkin,
  • O. B. Petrova

摘要

Color changes of the natural gemstones zircon, andradite, and cassiterite during their heat treatment in various media have been studied. Initially almost black zircons turned pale-yellow after heating at 1100°C under oxidizing conditions (air oxygen); bright blue, at the same temperature under reducing conditions (carbon monoxide). Color reversibility in addition to such contrasting color changes was also noted in andradite, depending on the heat treatment medium. Crystals in a repeated series of experiments at the same temperature (830°C) in air turned light brown; in the presence of a reducing agent, returned to a saturated green color. Thus, the key factor determining the observed color changes was the heating medium.