Unless otherwise stated, all gemstones are assessed and graded in their mountings. Approximate weights and average quality grades adhere to the Gemological Institute of America (GIA) grading scale. Mountings prohibit full and accurate observation of gem quality and weight. Therefore, all information regarding mounted gemstones should be considered an estimate unless accompanied by an independent laboratory report (such as GIA, AGL or EGL).
Major diamonds are graded with the use of pre-graded permanent master diamonds color comparison stones and the grading nomenclature prescribed by the GIA. Colored Gemstones are graded using the GIA prescribed colored stones grading system and nomenclature. Major colored stones are described using Gem Dialogue color grading system.
The authenticity, antiquity, decorative periods, vintages and or circa dating are determined to the best of our knowledge. This determination is based on materials used, manufacturing techniques, design characteristics, hallmarks and makers marks, lapidary techniques, technological developments and consultation of our extensive reference library and materials. It is important to note dating and period attributions are not an exact science, as decorative periods often overlap and draw inspiration from one another.