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How to Identify Jade

Jadeite vs nephrite, A/B/C treatments, and the tests professionals use — a Singapore buyer's guide

Singapore sits in the middle of the world\'s jadeite trade: the finest material is mined in Myanmar, cut in Guangzhou and Hong Kong, and sold across Southeast Asia — including here. Yet "jade" is one of the most abused words in jewellery. This guide explains what jade actually is, what the A/B/C labels mean, and how professionals tell real from treated from fake.

Two different stones are both called jade

Gemmology recognises two distinct materials as jade: jadeite (a pyroxene, the imperial-green stone of Asian jewellery, roughly refractive index 1.66 and specific gravity about 3.3) and nephrite (an amphibole, tougher and usually darker green to white, refractive index about 1.62 and specific gravity 2.9–3.0). Imperial Burmese jadeite is the precious one; much antique "Chinese jade" and most New Zealand greenstone is nephrite. They can look similar to the eye and are separated decisively by refractive index and specific gravity — two of the first measurements taught in instrument-based gemmology.

What Type A, B and C jade really mean

The letters describe treatment, not quality:

Grade	Meaning	What to know
Type A	Natural jadeite, untreated except classic wax polishing	The collector\'s stone; certified by laboratories precisely because B/C imitate it
Type B	Bleached and polymer-impregnated jadeite	Acid bleaching removes stains, then polymer fills the fractures; translucency looks flattered at first, degrades over years
Type C	Dyed jadeite	Colour is artificial; often also bleached (B+C)

Why this matters in Singapore: A-grade and B-grade jadeite can sit side by side in a display at similar prices, and the difference is tens of thousands of dollars per piece at the top end. A laboratory certificate (see our Singapore gem labs guide — NGI in particular specialises in jadeite) exists precisely to settle this question.

How professionals test jade

• Refractive index — jadeite (~1.66) vs nephrite (~1.62) vs look-alikes; measured on a refractometer in seconds.
• Specific gravity — jadeite is noticeably denser (~3.3) than most simulants; hydrostatic weighing settles it.
• Magnification — acid-bleaching leaves an eroded "orange-peel" structure and polymer fills show as unnatural fracture textures under the microscope; dyed colour concentrates in surface-reaching cracks.
• UV light — many polymers fluoresce under long-wave UV where natural jadeite stays inert.
• Spectroscopy — advanced labs use it to confirm polymer and dye; this is laboratory territory, not a loupe test.

Red flags when buying jade in Singapore

• Prices that seem impossible for "imperial" colour — the most treated and imitated material on the market.
• Certificates that describe colour and translucency but never state treatment status. A jade certificate without a treatment opinion is not doing its job.
• "Old jade" stories attached to freshly polymer-filled stones. Age is provenance, not proof.
• Dealer reluctance to let an independent laboratory re-examine the piece.

Where jade comes from

Nearly all gem jadeite comes from northern Myanmar (Kachin State); nephrite comes chiefly from Xinjiang, British Columbia and New Zealand, plus the Polar Range in Siberia. See these sources pinned on our Gem Globe — jade\'s geography explains its trade routes, its pricing and its counterfeits.

Educational content by the gemmology faculty of the Jewellery Design & Management International School (JDMIS), Singapore. Gemmological constants quoted are standard reference values.