Gemstone Assessment and Grading
Unless otherwise noted, all gemstones are assessed and graded while still mounted in their settings. We provide approximate weights and quality grades based on the Gemological Institute of America (GIA) grading scale. Please be aware that mountings can restrict a complete evaluation of gem quality and weight, so all information regarding mounted gemstones should be regarded as estimates unless accompanied by an independent laboratory report (such as from GIA, AGL, or EGL).
Diamond Grading: Major diamonds are graded using pre-graded permanent master diamonds for color comparison, following the GIA's prescribed nomenclature.
Colored Gemstones: These are graded according to the GIA's colored stones grading system and terminology. Major colored stones are described using the Gem Dialogue color grading system.
Authenticity and Dating
The authenticity, antiquity, decorative periods, and approximate dating of our pieces are determined to the best of our knowledge. This assessment is based on materials used, manufacturing techniques, design characteristics, hallmarks, makers' marks, lapidary methods, and our extensive reference library.
Please note that dating and period attributions are not exact sciences; decorative periods often overlap and influence one another.