Nephrite jade: the other true jade

Nephrite is one of the two true jades, and the older one: the jade of ancient Chinese carving, of Maori pounamu and of Stone Age axes. As a stone, nephrite jade is a dense mass of fine amphibole fibers with a soft, greasy luster, usually white, green, brown or black, and it is the toughest of all gem materials.

Nephrite at a glance

Property	Nephrite
Mineral	Amphibole, tremolite-actinolite series
Chemistry	Calcium magnesium iron silicate, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
Structure	Dense aggregate of fine, felted fibers
Mohs hardness	6 to 6.5
Specific gravity	About 2.95
Refractive index	1.606 to 1.632
Luster	Soft, greasy to waxy
Transparency	Translucent to opaque
Toughness	Very high; no cleavage, splintery fracture

The figures are GIA’s reference values. The structural description follows the Wyoming State Geological Survey.

Is nephrite jade real jade?

Yes. Gemologists recognize two jades, nephrite and jadeite, and historically the word jade referred mainly to nephrite. GIA notes that Stone Age people in China, Europe and elsewhere shaped nephrite into axes, knives and ritual objects, and that nephrite carving has flourished in China for more than 3,000 years.

What made it useful then is what defines it now. The matted fibers make nephrite the toughest of gem materials, according to Gem-A. On the comparative toughness figures GIA publishes, nephrite scores 225,000 against 120,000 for jadeite. It also rings musically when struck.

In Chinese, nephrite is sometimes called ruanyu (软玉), “soft jade”, against “hard jade” for jadeite. The label misleads: nephrite is only about half a Mohs step softer and is harder to break. The two stones are compared property by property in jadeite vs nephrite.

Nephrite colors: white nephrite jade to black nephrite jade

Color follows chemistry. Magnesium-rich nephrite close to tremolite is light, down to creamy white. Iron-rich nephrite toward actinolite is green, and darker with more iron. Brown often comes from oxidized iron, and yellow and gray tones from other elements and inclusions.

Chinese dealers sort the material into color categories:

Category	Chinese name	Notes
White	baiyu (白玉)	The traditional favorite in China
Greenish white	qingbai yu (青白玉)	Between white and gray-green
Gray-green	qingyu (青玉)	The most abundant
Spinach green	biyu (碧玉)	Colored by iron; the most prized color for many Western buyers
Yellow	huangyu (黄玉)	Rare
Sugar	tangyu (糖玉)	Brown
Black	moyu (墨玉)	See below

White nephrite. A Gems & Gemology study of white nephrite describes the best Xinjiang material as white with a greasy luster, known in the trade as mutton fat jade, and says white nephrite from Xinjiang has kept the highest price in the Chinese market. The grade and its pitfalls are covered in mutton fat jade, and the color more broadly in white jade.

Green nephrite. Siberian spinach-green material is the classic example, and it often carries black graphite specks.

Black nephrite. Chinese dealers separate two black types. Moyu, “ink jade”, is nephrite that dealers say is blackened by graphite. It grades into white-and-black pieces that resemble ink paintings, called qinghua (青花). Heiqing (黑青), “black-green”, is an extremely dark member of the gray-green family that looks black in the hand but shows green on thin edges or under a strong light. Black jade covers both, along with black jadeite.

Where nephrite comes from

The historical source is the Kunlun Mountains of Xinjiang in western China, around Hetian (formerly Khotan). Gem-A reports that production there is shrinking. Today nephrite also comes from:

• Russia, in the Lake Baikal region
• Qinghai, in China
• South Korea, at Chuncheon
• British Columbia in Canada, which now supplies much of the market
• Wyoming, Alaska and California in the United States
• New Zealand, where it is pounamu, the Maori greenstone
• South Australia and Taiwan

“Hetian jade” is a mineral name, not an origin

Historically, Hetian jade meant jade from the Hetian area of Xinjiang. In today’s Chinese trade and on Chinese test certificates, Hetian yu (和田玉) names the mineral. Any tremolite nephrite that meets the national standard GB/T 38821-2020 is certified as Hetian jade whether it was mined in Xinjiang, Qinghai, Russia, Korea or elsewhere.

Origin still drives price, and it is very hard to prove. The Gems & Gemology study notes that white nephrite from Baikal, Chuncheon and Qinghai is difficult to tell from Xinjiang material with the unaided eye or even under a microscope, and that stone from other places has been falsely sold as Xinjiang nephrite to fetch higher prices. Dealers say the same thing: most white nephrite sold in China today is Russian or Qinghai material, Xinjiang white is scarce, and at the top grades experts cannot separate the origins by eye.

At lower and middle grades dealers do describe regional habits. Qinghai nephrite tends to be the most translucent, with a watery or glassy look and frequent translucent streaks called water lines (shui xian, 水线). Korean nephrite tends to have a waxy, candle-like surface where good nephrite looks oily. Dealers’ own advice is to judge the stone and treat any origin story as unproven.

How nephrite is judged

The first thing a Chinese dealer looks for is the oily look, described with the words you (油) and run (润): a surface that seems greasy and moist. After that come fineness of texture, evenness of color and freedom from cracks and spots.

Translucency is not the goal. In jadeite, more translucent is better. In nephrite, very translucent material has traditionally been marked down.

Under a strong side light, natural nephrite usually shows some internal texture: the interwoven fibers, faint mottling or water lines. Dealers treat this as normal. They are more suspicious of a cheap white piece that looks perfectly uniform and structureless, which they say is more likely to be treated or man-made than a bargain.

Seed material and mountain material

Nephrite is also sorted by how it was found. Mountain material (shanliao, 山料) is quarried from the primary deposit and comes out as angular blocks with no skin. Seed material (ziliao, 籽料) broke off, was carried down rivers and tumbled into rounded pebbles and boulders, often with an iron-stained skin. Partly rounded pieces that traveled only a short way are called mountain-stream material (shan liu shui, 山流水).

Seed material carries a premium, but it is not automatically better. The river sorts out weak stone, yet pebbles can still carry iron-stained cracks, and good mountain material can be just as fine and white. The premium paid for pebbles and their skins has also produced a large trade in fakes.

Imitations to know about

Three stones commonly stand in for nephrite:

• Quartzite is granular with a glassy luster, and at a specific gravity of about 2.65 it feels lighter in the hand.
• Marble, sold in China as “Afghan jade”, is often banded and is only about 3 on the Mohs scale, so a knife scratches it.
• Serpentine is softer than nephrite and can often be scratched with a knife.

Nephrite is rarely dyed, according to the International Gem Society, but dyed and artificially tumbled “river pebbles” are a known problem. Looking and handling narrow things down, and a gemological laboratory report settles whether a stone is nephrite and whether it has been treated. The home checks are in how to tell if jade is real.

What nephrite is worth compared with jadeite

Nephrite is more abundant than jadeite and generally less expensive. GIA notes that for most nephrite, larger size does not raise value dramatically, and carved pieces are valued one by one on material, artistry and provenance.

The best can still be very costly. Gem-A records a green nephrite seal of the Qianlong emperor selling for US$15.7 million at Sotheby’s Hong Kong in 2010. That is the price of an imperial object, not a guide to what nephrite jewelry sells for.