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.

No abstract

No abstract

The beauty of gems and minerals have been examined and appreciated by optical tools for centuries. Current methods for examining the interior structure of gems and minerals typically requires a sample to be cut and polished prior to imaging. In this presentation, we introduce a new tool for imaging gems and minerals in three dimensions, the multiphoton microscope. We have demonstrated that the multiphoton microscope can capture fascinating information from natural gems and minerals with sub-micron resolution at depths up to the millimeter scale. This new application of multiphoton microscopy may open the doors to non-destructive characterization leading to new information on the formation, structure, and appearance of these stones that have fascinated the eye for centuries.