How to tell if jade is real

What real jade is, and what gets sold as jade

Jade is a trade name for two different minerals. Jadeite is a pyroxene and nephrite an amphibole; they look so alike that science only separated them in 1863. Both earn the name through toughness rather than hardness: their interlocking crystals resist breaking better than almost any other stone, which is why nephrite made Neolithic axes. Everything else sold as jade is a substitute wearing a place name.

The substitutes follow a pattern. Serpentine becomes “new jade” or “Korean jade”, aventurine quartz becomes “Indian jade”, and green-dyed calcite or travertine becomes “Mexican jade”. US Federal Trade Commission jewelry guides treat misleading varietal names as deceptive, yet the names persist on market stalls and in online listings — so the label on a piece is where testing starts, not where it ends.

The home checks, in order

Every check here is non-destructive, and that is the point. A finished bangle or pendant should never meet a steel nail: a scratch test that proves serpentine has also ruined the piece. Work the four checks in order, because each one retires more fakes than the one after it.

1. Step 1Backlight itPress a small flashlight to the back of the piece in a dark room. Round bubbles or swirl lines mean glass, glittering flakes mean aventurine, and color concentrated along cracks means dye.
2. Step 2Read the textureWith the same light, jadeite shows a granular, sugary structure and nephrite a fibrous, felted one. An even, structureless glow belongs to glass, plastic or dyed chalcedony.
3. Step 3Weigh it twiceA kitchen scale and a cup of water give specific gravity. Jadeite lands near 3.34 and nephrite near 2.95, while serpentine and quartz lookalikes sit between 2.5 and 2.7.
4. Step 4Look for wearPut a loupe on raised edges and high points. Serpentine and dyed calcite collect scuffs and rounded edges from ordinary use; jade holds a crisp polish for decades.

The kitchen-scale density test

Specific gravity is the one number a household can measure well enough to matter, and it splits jade from its commonest substitutes. You need a scale that reads to 0.01 gram, a cup of water and a length of thread. The test works only on loose pieces: a metal setting, a hollow bead or a glued join falsifies the answer.

A worked example shows why a pocket scale is enough. A 12.00-gram pendant of jadeite at 3.34 displaces 3.59 grams of water. The same pendant in nephrite at 2.95 displaces 4.07 grams, in aventurine at 2.65 about 4.53 grams, and in serpentine at 2.55 about 4.71 grams. Gaps of half a gram and more are far beyond the error of a 0.01-gram scale, which is why this check outperforms every folk test below.

The number narrows; it does not certify. Glass varies too widely in density to be ruled in or out this way — the flashlight catches glass instead — and nephrite overlaps with a few rare lookalikes that only instruments separate.

Flashlight, hair and ring tests: what they actually show

The popular jade tests are not useless. They answer a narrower question than the one people ask, and each has a lookalike that passes it too.

The flashlight is the only one of these worth keeping, and only because of what it reveals inside — bubbles, flakes and dye — rather than because light passes through.

A, B and C jade: where home testing stops

Commercial jadeite is graded by what was done to it. Type A carries only the traditional wax finish and holds its value. Type B has been bleached in acid and impregnated with polymer resin under pressure: it looks better at first, can turn brittle and discolor within a few years, and sells for a small fraction of Type A. Type C is Type B with dye added. Detecting Type B usually takes laboratory testing.

A density check can show a piece is jadeite. No home check can show it is untreated jadeite — and that difference is most of the price.

That boundary is the same one the gem identifier key prints in its third column: species at home, treatment at a lab. Anything bought as untreated jadeite, priced as an heirloom or headed for resale earns a report from a gemological laboratory before money changes hands. The fee is a small fraction of what Type A jadeite sells for.

Found jade versus finished jade

Everything above assumes a finished piece you must not damage. A rough green pebble from a creek or beach is a different problem with blunter tools: a steel nail on a hidden spot, a fresh chip, a close look at a broken face. Those checks, and the serpentine, malachite and epidote they separate, live in green rock identification. In the United States the classic nephrite ground is central Wyoming around Jeffrey City and Crooks Gap, where jade turns up as stream-rounded pebbles and boulders.

A rough find that passes and might be worth money goes through the elimination order in how to identify valuable rocks before any appraisal. Two neighbors share jade’s problem of convincing fakes: dyed chalcedony and banded slices, covered in how to identify agate, and opal, whose assembled and lab-grown versions are sorted in how to tell if opal is real.