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Jade vs Serpentine: Hardness, Texture and Magnetism Clues

Jade is a gem and cultural term applied principally to two unrelated mineral materials: nephrite and jadeite. Serpentine minerals and serpentinite are common green look-alikes, especially in rough, carvings, and polished stones. Colour alone is not diagnostic. Nephrite's tightly interlocking fibrous texture makes sound material exceptionally tough, while many serpentinite specimens are softer, may scratch with a knife, and can contain weakly to moderately magnetic zones. Treatments, mixed rocks, weathering, and polished surfaces can mask field properties, so valuable material belongs with a qualified gemological laboratory. On suitable rough, knife scratching and texture are useful screening clues: many serpentine-rich materials are softer and scratch more readily, while sound nephrite normally resists a steel knife and lacks the granular sparkle of quartz-rich look-alikes. Localized magnetism supports serpentinite but does not identify every sample. Jadeite, nephrite, serpentine, treatments, and assembled material can require gemological testing. Record whether the object is rough, polished, carved, treated, inherited, or sold under a trade name. Do not treat the seller's label as a mineral identification. Inspect multiple surfaces with a hand lens for felted fibres, granular sparkle, veins, soft-looking zones, dye concentrations, coatings, or assembled layers. Test magnetism gently at several points. Localized attraction can support magnetite-bearing serpentinite, but absent attraction does not prove jade. Only on inconspicuous expendable rough, and only with permission, use a light steel-knife test. A scratch supports softer serpentine-rich material; failure to scratch does not authenticate jade. Avoid density conclusions from hand heft alone. If appropriate, use a calibrated hydrostatic specific-gravity measurement on an unmounted, stable specimen and account for cavities, attached material, and water sensitivity. Do not use destructive scratch tests on carvings or gems. Preserve any provenance, receipts, treatment disclosure, and earlier laboratory reports. For purchase, insurance, sale, cultural attribution, or a valuable object, obtain a report from a qualified independent gemological laboratory. The word jade does not describe one mineral species. Nephrite and jadeite have different mineralogy and properties, and commercial names may be used inconsis