Quality Assessment of Natural Jadeite: Process and Tips for Appraisers

Posted on August 8, 2020 by Roland Schluessel, FGA, DGemG

Most retailers and appraisers in the Western World lack the knowledge to judge the quality parameters and value of natural untreated jadeite. This is because natural jadeite material in all qualities is scarce in the western marketplace, and because they lack literary references to rely upon. INTRODUCTION Most publications about jadeite grading discuss the various treatments but not the actual quality grading of natural untreated jadeite. While there are standards for quality grading of jadeite jade (Cantonese: Fei Cui) in Hong Kong and in mainland China (Mandarin: Fei Tsui), there are only a few publications about the subject in non-Chinese language. The author offers a simplified step-by-step method to assess the main quality parameters of natural un-treated jadeite, also known as “Type A” in the trade. This systematic approach forms the foundation for a consistent appraisal. The whole concept involves the following steps: Step 1: Identification of the gemstone species. Step 2: Identification of treatment(s).Step 3: Quality assessment: QA1a) Judging the quality of the base: grain size and diaphaneity. QA1b) Judging the evenness of the texture: look for textural imperfections and structural flaws. QA2a) Judging the clarity: extent, size, and color of inclusions. QA2b) Judging the purity: presence and type of fissures and fractures. QA3) Judging the type of base: classification of the base and luster. QA4a) Judging the color: hue, tone, saturation. If present, identify secondary color. QA4b) Judging the evenness of color.QA5) Judging the make: shape, proportions, outlines, polish quality.QA6) Judging the volume: volume is better than size. Step 4: Valuation and appraisal. This article focuses on the assessment (processes listed as QA under step 3) of nine parameters that define quality and value of all color varieties of natural Burmese jadeite. However, it is advised to previously identify the gemstone species submitted for appraisal. Standard gemological tools might be sufficient for an experienced gemologist to support a reliable identification, but one should keep in mind that jadeite is a polycrystalline aggregate which is part of a solid solution series with omphacite, kosmochlor and aegirine, and that amphibole- group minerals and plagioclase feldspar (e.g., albite)...

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