Method and system for determining the location of artefacts and/or inclusions in a gemstone, mineral, or sample thereof

A system for determining a location of artefacts and/or inclusions in a gemstone, mineral, or sample thereof, the system comprising:

• a surface mapping device arranged to surface map a gemstone, mineral, or sample thereof to determine surface geometry associated with at least a portion of a surface of the gemstone, mineral or sample thereof using one or more of X-ray computed tomography, optical coherence tomography, laser scanning, and structured illumination;
• a sub-surface mapping device arranged to sub-surface map the gemstone, mineral, or sample thereof using an optical beam that is directed at the surface along an optical beam path, wherein the optical beam is generated by an optical source using one or more of optical coherence tomography and optical projection tomography;
• a computing system arranged to:
• determine a surface normal at the surface at an intersection point between the optical beam path and the determined surface geometry,
• determine relative positioning between the surface normal and the optical beam path, and
• determine the location of artefacts and/or inclusions in the gemstone, mineral, or sample thereof based on the sub-surface mapping step and the determined relative positioning;
• wherein the surface of the gemstone, mineral, or sample thereof is untreated and surface mapping and sub-surface mapping are performed without refractive index matching.