Priya Nair
Why so much "jade" isn't jade
True jade is one of only two minerals: jadeite, the hard, dense stone long prized in Chinese carving, and nephrite, the softer, more plentiful material used for centuries in New Zealand, Russia and China. They look related, but they are chemically different — and the price gap between them, and between either of them and their imitations, is enormous. That gap is exactly why the market is full of glass, serpentine, dyed quartzite and treated stone sold under names designed to sound authentic. Four or five simple checks will steer you past most of it.
First checks: colour, surface and light
Hold the piece under a bright lamp and examine the surface closely.
- Colour is uneven. Real jadeite rarely gives an even wash of green. Look for colour zoning — patches, streaks and root-like veins drifting through the stone. A perfectly uniform colour across a large carved piece is suspicious.
- The polish is deep. Jadeite takes a hard, mirror-like polish. Nephrite has a characteristic greasy, soapy sheen. Glass imitations look glossy but flat, almost wet.
- Light diffuses inside. Hold the piece against a phone torch. Genuine jade glows softly and the light spreads within it, often revealing internal structure. Glass transmits light too cleanly and completely.
- No bubbles. Under a 10x loupe, glass shows round gas bubbles and swirling flow lines. Jade never does.
The hand test: weight, coolness and tone
Jadeite has a specific gravity of roughly 3.3, nephrite about 2.95, while glass and serpentine sit around 2.5 to 2.6. Pick up two pieces of similar size and the difference is obvious: jade feels noticeably heavier and denser in the palm, almost as if it has been overfilled. It also feels cold at first and warms slowly, whereas glass takes on your hand's warmth within seconds.
Tapping is useful on bangles, discs and loose cabochons. Rest the piece on your fingertips and tap it lightly with a coin. Jade rings clear and sustained, with a faint musical quality. Glass, serpentine and soapstone answer with a dull thud. Never tap mounted jewellery — you risk loosening a setting or chipping a stone.
The usual impostors, and how they give themselves away
- Serpentine — sold as "new jade", "Korean jade" or "Styrian jade". It is genuinely soft, around 2.5 to 4 on the Mohs scale, so it scratches and dulls with wear, feels light and sounds flat when tapped.
- Dyed quartzite — often labelled "Malaysian jade". Quartz has a sugary, grainy look under magnification, and the dye sits in the gaps between the grains.
- Glass — sometimes called "Peking glass". Bubbles, swirl marks and chips with curved, shell-like fracture surfaces are the giveaway.
- Aventurine, chrysoprase, prehnite and grossular garnet — all natural green stones, all sometimes sold loosely as jade. Aventurine sparkles with tiny metallic flecks; chrysoprase is a flat, uniform apple green with no colour zoning at all.
- Soapstone — extremely soft, easily marked with a fingernail, and unmistakably light.
What dye and treatment look like
Bleaching followed by polymer impregnation ("B-grade") and dyeing ("C-grade") are common in jadeite. These are treatments rather than outright fakes, but they must be declared and priced accordingly. With a loupe and a small torch, look for:
- Dye concentrated along cracks, forming fine coloured lines like a spider's web.
- Colour pooling in surface pits and grain boundaries rather than sitting within the stone.
- A faintly waxy or resinous surface, where polymer filling has dulled the polish.
- Patches of colour that do not match the surrounding tone when the piece is backlit.
Avoid a scratch test on someone else's stock — it is rude and easily damages soft imitations. If a seller invites you to test an inconspicuous spot on a low-value piece, a steel pin will mark serpentine and soapstone but slide harmlessly across jadeite.
Buying wisely
Ask directly: is this jadeite or nephrite, is it natural, and has it been treated? A straight answer, given comfortably, tells you as much as the stone does. Get the description written on your receipt, including the words jadeite or nephrite rather than a trade name.
Treat evocative labels with scepticism. Names built around places — "Korean", "Malaysian", "African", "Indian" — rarely describe jade at all. If a strand of vivid, translucent green beads is offered for the price of a meal out, it is not jadeite; strong green jadeite of good clarity is rarer and more valuable by weight than gold.
Finally, remember that nephrite is genuine jade and perfectly lovely. Much antique carving, from Maori hei-tiki to Qing dynasty pieces, is nephrite, and it deserves to be bought and enjoyed as such. For anything costing more than a few hundred pounds, an independent gemmological report is money well spent. A knowledgeable seller will welcome the questions — and if they flinch at them, walk away.
