The most reliable way to tell jade from serpentine is the scratch test: true jade (both jadeite and nephrite) is significantly harder than serpentine and will resist scratching from a steel knife, while serpentine scratches easily. But hardness is just one of several tests you can do at home or with basic tools. Color alone won’t help you, since high-quality serpentine can look nearly identical to jade, and sellers routinely exploit that resemblance.
Why Serpentine Gets Sold as Jade
Serpentine is one of the most common jade imitations on the market, and it’s often sold under names designed to make you think you’re buying the real thing. “New Jade,” “China Jade,” “Korea Jade,” “Siberian Jade,” and “Ocean Jade” are all trade names for serpentine, not jade. The list is long: Anden Jade, Pilbara Jade, Souchow Jade, and dozens more are serpentine rocks marketed with the word “jade” attached. If the name includes a geographic qualifier followed by “jade,” treat it as a red flag and test the stone before trusting the label.
One variety of serpentine, formerly called bowenite, can reach a Mohs hardness of 5 to 6, which puts it close to nephrite’s range and makes it particularly convincing. In some mining regions, serpentine and nephrite actually form in the same deposits, so even the source location doesn’t guarantee what you’re getting.
The Scratch Test: Hardness
This is the simplest and most decisive home test. On the Mohs hardness scale, jadeite rates 6.5 to 7, nephrite rates 6 to 6.5, and most serpentine falls between 2.5 and 5.5. A standard steel knife blade has a hardness of about 5.5. If you can scratch the surface of the stone with a knife (test on an inconspicuous spot), it’s almost certainly serpentine. True jade will resist the blade entirely or leave only a faint metallic streak from the knife itself.
For a more precise test, use a piece of quartz (hardness 7). Quartz will scratch nephrite but won’t scratch most jadeite. Neither quartz nor a steel blade should leave a visible groove in real jade the way they will in serpentine. Keep in mind that bowenite serpentine, at hardness 5 to 6, sits in a tricky middle zone. A steel knife may barely scratch it. If the result seems borderline, move on to the other tests below.
The Heft Test: Density
Pick up the stone. Jade is noticeably denser than serpentine, and experienced buyers can often feel the difference just by holding the two side by side. Jadeite has a specific gravity of 3.3 to 3.5, nephrite ranges from 2.9 to 3.0, and serpentine is lighter than both, typically falling around 2.5 to 2.6. A piece of jadeite will feel surprisingly heavy for its size, like a river pebble rather than a dry garden stone.
If you want a precise measurement, you can do a water displacement test at home. Weigh the stone dry, then suspend it in water on a string and record the weight difference. Dividing the dry weight by the weight of the displaced water gives you the specific gravity. A reading above 2.9 points toward nephrite; above 3.3 strongly suggests jadeite. Anything below 2.7 is almost certainly serpentine.
Surface Luster and Texture
When polished, jadeite has a glassy, vitreous luster, almost like looking at a wet hard candy. Nephrite and serpentine both have a greasy or waxy luster, which makes them harder to tell apart by shine alone. However, the surface texture offers more clues.
Look at the stone under good light, ideally with a 10x loupe. Serpentine often shows a network of lighter-colored lines running through the surface, creating a pattern that resembles lizard skin or cracked mud. These net-like structures are a strong indicator of serpentine. Nephrite, by contrast, has a smooth, even texture that comes from its tightly matted internal fibers. You won’t see that webbed cracking pattern in genuine nephrite.
Both serpentine and nephrite can contain small black inclusions, so dark spots alone don’t distinguish them. But if those black specks are magnetic (test with a small magnet), that’s another point toward serpentine, which commonly contains magnetite grains.
The Sound Test
This classic test works best with bangles, beads, or thin carved pieces. Tap two pieces together, or tap the stone gently with a coin. Real jade produces a clear, bright, resonant ring that sustains for a moment, sometimes compared to a piano note. Serpentine produces a duller, flatter sound with little resonance, more like tapping on plastic or a muted drum.
The sound difference comes from internal structure. Nephrite’s tightly interlocked fibers and jadeite’s dense intergrown crystal grains both transmit vibration efficiently. Serpentine’s looser grain structure absorbs the vibration instead of carrying it. This test takes a little practice, and it works best when you have a known piece of jade to compare against. On its own, it’s not conclusive, but combined with other tests it adds confidence.
Internal Structure Under Magnification
If you have access to a loupe or a strong magnifying glass, the internal grain gives each stone away. Jadeite is made up of granular crystals tightly interlocked like a mosaic. Nephrite is composed of finely matted, fibrous bundles, almost like compressed felt. This matted fiber structure is what makes nephrite extraordinarily tough, even tougher than jadeite despite being slightly softer.
Serpentine’s internal structure is less organized. In antigorite serpentine (the most common jade impostor), you’ll often see those characteristic bright, net-like patterns and a more uneven grain. The surface may also show subtle pitting or unevenness in polished areas that jade wouldn’t display, because serpentine’s softer patches wear down unevenly during cutting and polishing.
Thermal Feel
Jade is often described as feeling cool to the touch, and this has some basis in physics. According to testing at the Gemological Institute of America, jadeite has measurably higher thermal inertia than nephrite, meaning it pulls heat from your skin faster and feels cooler. Serpentine, being less dense and having different thermal properties, warms up more quickly in your hand.
Hold the stone against your cheek or the inside of your wrist. Jadeite will feel distinctly cold and stay cool for several seconds. Nephrite will also feel cool but warms slightly faster. Serpentine reaches skin temperature relatively quickly. This isn’t a standalone test, but it’s a useful quick check when you’re handling stones at a market or shop.
Putting the Tests Together
No single home test is foolproof, especially with higher-quality serpentine varieties like bowenite that overlap with jade in hardness. The most reliable approach combines at least three tests. Start with the scratch test to eliminate most serpentine. Check the heft to confirm density. Then look at the surface under magnification for the telltale lizard-skin cracking of serpentine versus the smooth, even texture of jade.
If you’re buying an expensive piece and still uncertain, a gemological laboratory can give a definitive answer using refractive index measurements. Nephrite reads between 1.60 and 1.62, jadeite sits at 1.65 to 1.68, and serpentine falls in a lower range. This test requires professional equipment but leaves no ambiguity. For anything you’re spending serious money on, lab certification is worth the modest fee.