Thermochromic gemstone evaluation using temperature controlled in situ absorption spectroscopy

Area of Science:

• Gemology
• Materials Science
• Spectroscopy

Background:

• Thermochromic gemstones change color with temperature and light, but their underlying mechanisms and defects are poorly understood due to experimental limitations.
• Current analytical techniques struggle to capture rapid and subtle color changes in gemstones, hindering research into thermochromism and photochromism.

Purpose of the Study:

• To introduce a novel in situ absorption spectroscopy system for analyzing thermochromic and photochromic gemstone responses.
• To investigate the defect mechanisms responsible for color changes in gemstones under varying temperature and light conditions.

Main Methods:

• Developed an in situ absorption spectroscopy system with precise temperature control and external illumination for real-time monitoring.
• Applied the system to study the color-changing chameleon diamond and yellow 480 nm band diamond.

Main Results:

• The system successfully detected subtle and rapid color changes in both faceted and rough gemstones.
• Provided valuable insights into the specific mechanisms driving thermochromic color changes in diamonds.

Conclusions:

• The developed spectroscopy system effectively analyzes thermochromic and photochromic responses in gemstones.
• Offers a new method for studying optical responses and defects in materials under controlled temperature and excitation.
• Enhances understanding of gemstone color-change phenomena and associated optical defects.