3D Imaging of Gems and Minerals by Multiphoton Microscopy

TL;DR

This study employs multiphoton microscopy to explore the nonlinear optical properties of 36 gemstones, enabling three-dimensional imaging and analysis of crystal orientations, thus providing a novel approach for gemstone examination.

Contribution

It introduces the use of multiphoton microscopy for nonlinear optical characterization and 3D imaging of gemstones, revealing internal structures and crystal orientations.

Findings

Successful 3D imaging of gemstones up to millimeter depth.

Identification of crystal orientations via polarization-dependent signals.

Demonstration of multiphoton microscopy as a valuable tool for gemstone analysis.

Abstract

Many optical approaches have been used to examine the composition and structure of gemstones, both recently and throughout history. The nonlinear optical behavior of different gemstones has not been investigated, and the higher order terms to the refractive index represent an unused tool for qualifying and examining a stone. We have used a multiphoton microscope to examine the nonlinear optical properties of 36 different gemstones and demonstrate that it is a useful tool for imaging them three-dimensionally up to the millimeter scale below the sample surface. The polarization dependence of second harmonic generation signals was used to examine the crystal orientations inside the minerals.