Families & Minerals15
Jade玉 · yù¶
Two senses. Strictly, under modern mineralogy and China's national standards, jade means only tremolite jade (Hetian) and jadeite jade (fei cui). Broadly, following Xu Shen's definition — "jade is the fairest of stones" — any beautiful, workable stone qualifies, which is why serpentine, Dushan jade, turquoise, agate and rock crystal are traditionally counted as jade.
Nephrite软玉 · ruǎn yù¶
A dense aggregate of the tremolite–actinolite series of the amphibole family, Ca₂(Mg,Fe)₅[Si₄O₁₁]₂(OH)₂, whose felted fibrous texture makes it the toughest of natural gem materials. "Soft" marks only its Mohs 6–6.5 against jadeite's 6.5–7 — never a difference of quality. Current national standards name it "Hetian jade".
Jadeite (the mineral)硬玉 · yìng yù¶
The sodium-aluminium pyroxene NaAlSi₂O₆, monoclinic. As a mineral it is one principal constituent of fei cui; as a stone name, "hard jade" was long used for fei cui as a whole — a usage the CIBJO Jade Guide has now corrected to one member of the three-mineral Fei Cui system.
Hetian jade和田玉 · hé tián yù¶
The statutory name for tremolite jade. Under GB/T 38821-2020 it carries no geographic meaning: qualifying material from Xinjiang, Qinghai, Russia or Korea may all be called Hetian jade, and certificates do not state origin. In the strict sense it denotes the Kunlun–Altun belt of Xinjiang, some 1,260 kilometres from end to end.
Fei Cui / jadeite jade翡翠 · fěi cuì¶
A granular to fibrous polycrystalline aggregate composed solely or principally of jadeite, omphacite and kosmochlor, or any combination thereof (CIBJO Jade Guide, 2026). Named for the red and green plumage of the kingfisher; gem-grade material comes almost entirely from the Uru basin of northern Myanmar, reaching China by the Yunnan–Burma roads in the seventeenth century.
Tremolite透闪石 · tòu shǎn shí¶
Nephrite's principal mineral, usually above 95% by volume. By IMA nomenclature, amphibole with Mg/(Mg+Fe) ≥ 0.90 is tremolite. Pure tremolite is colourless; the degree to which iron replaces magnesium governs the shift from white through greenish-white to qing.
Actinolite阳起石 · yáng qǐ shí¶
Forms a complete solid-solution series with tremolite, at Mg/(Mg+Fe) between 0.50 and 0.90. Its higher iron content darkens the stone: spinach-green jade and the black-qing and black-bi jades are all actinolite-led.
Omphacite绿辉石 · lǜ huī shí¶
A calcium-sodium pyroxene, (Ca,Na)(Mg,Fe,Al)Si₂O₆, one of the three Fei Cui minerals. Omphacite-dominant jadeite reads ink-black in hand and glows green against the light — the stone called mo cui. Awkward to name under the old scheme, it gained proper standing with CIBJO's three-mineral definition.
Kosmochlor钠铬辉石 · nà gè huī shí¶
The chromium pyroxene NaCrSi₂O₆, one of the three Fei Cui minerals. Material dominated by it is intensely green but opaque — the trade's "dry green".
The Four Famous Jades四大名玉 · sì dà míng yù¶
Hetian jade of Xinjiang (tremolite), Xiuyan jade of Liaoning (serpentine), Dushan jade of Nanyang, Henan (a plagioclase rock) and turquoise of Hubei. Of the four, only Hetian jade is jade in the strict sense of the national standards.
Xiuyan jade岫岩玉 · xiù yán yù¶
Serpentine jade from Xiuyan, Liaoning, Mg₆[Si₄O₁₀](OH)₈ — yellow-green, waxy to vitreous, and soft at Mohs 2.5–6, scratchable with a pocket knife. It supplied the Hongshan culture and has been worked for over five thousand years. The district also yields tremolite "old jade", the river-milled hemo yu.
Dushan jade独山玉 · dú shān yù¶
A plagioclase rock from Dushan, Nanyang, Henan — many colours in one stone, green, white, violet and umber together, ideal for polychrome carving; hence "Nanyang jade". Already present among the finds at Yinxu.
Turquoise绿松石 · lǜ sōng shí¶
A hydrated copper-aluminium phosphate, sky-blue to apple-green, finest from Shiyan in Hubei. The dragon-form mosaic from Erlitou — over seventy centimetres long, of more than two thousand tesserae — attests its ceremonial rank thirty-seven centuries ago.
Albite jade ("water foam")水沫子 · shuǐ mò zi¶
Albite jade, NaAlSi₃O₈, found alongside jadeite and usually white; held to the light it shows clouds of impurity specks like foam on water. At RI 1.52–1.53 and SG 2.6–2.63 it falls well below both jadeite and nephrite, yet is often passed off as white jade or ice-grade fei cui.
"Afghan jade" (marble)阿富汗玉 · ā fù hàn yù¶
A fine marble, (Ca,Mg)CO₃, also called "Pakistani jade" after its usual import route. Close-grained and white, it mimics Hetian white jade — but at Mohs 3 it lacks all unction, and fizzes violently in dilute hydrochloric acid, the quickest test of all.
Nephrite Colours14
Mutton-fat white jade羊脂白玉 · yáng zhī bái yù¶
The summit of nephrite, judged by four "highs": unctuousness, whiteness, fineness and purity — a congealed, faintly warm white of strong greasy lustre, with no grain visible under raking light. It comes almost exclusively from river pebbles. No national standard defines it, so the shop term "mutton-fat grade" is largely commercial.
White jade白玉 · bái yù¶
Nearly pure tremolite with minimal iron substitution (no 3658 cm⁻¹ Raman band). Its purity and density give it the highest hardness of any colour class — measured Mohs averaging 6.39, peaking at 6.90. Folk grades include fish-belly, pear-blossom and moon white.
Greenish-white jade青白玉 · qīng bái yù¶
The transition class between white and qing, with moderate Fe²⁺ substitution. Temperate and reserved, it is the most numerous class among surviving works — hence its separate listing in the national standard.
Qing jade (grey-green)青玉 · qīng yù¶
The deepest Fe²⁺ substitution, with measured iron rising from 1,336 ppm in white jade to 17,309 ppm in dark qing. The most abundant class and the largest in block size — the Qing court's monumental jade mountains were carved from it. Folk names run from shrimp and willow to crab-shell, bamboo-leaf and oleaster green.
Oleaster green沙枣青 · shā zǎo qīng¶
The most prized of the qing jades — the grey-green of an oleaster leaf's underside, exceptionally fine and even in grain with a heavy unction, chiefly from Qinghai and the Ruoqiang district of Xinjiang.
Spinach-green jade碧玉 · bì yù¶
The only class born of altered ultramafic rock, actinolite-leaning, its green led by Fe²⁺ with chromium, manganese and nickel assisting. Chromite black dots are its birthmark. Densest of all classes (SG averaging 3.00). Alone among the colours, spinach jade is prized the more translucent it is.
Yellow nephrite黄玉 · huáng yù¶
A primary colour, chiefly from Ruoqiang in Xinjiang, coloured by iron and manganese together, the yellow strengthening as the Fe³⁺/Fe²⁺ ratio falls. Note: the Chinese term huang yu means yellow nephrite, not the gemstone topaz.
Chicken-fat yellow鸡油黄 · jī yóu huáng¶
The finest tone of yellow nephrite — the hue of congealed chicken fat, saturated yet still unctuous. Exceedingly scarce, and rivalling mutton-fat white in worth.
Sugar jade糖玉 · táng yù¶
Nephrite's only secondary colour: X-ray diffraction confirms goethite, FeO(OH), and kindred iron minerals seeping along grain boundaries and micro-fissures. Xinjiang's local standard grades it by coverage — trace below 5%, present 5–30%, "sugar-X jade" 30–85%, sugar jade above 85%. The sugar-white of Tashsayi, Qiemo, is the most celebrated.
Black nephrite墨玉 · mò yù¶
Three different stones share the name, each blackened by a different cause: graphite black (coloured by graphite inclusions), black-qing and black-bi (by iron-rich actinolite). Strong transmitted light separates them — the first stays opaque, the others glow qing and green. The classics call it "dark jade".
Blue-flower jade青花 · qīng huā¶
Black jade in which graphite makes up less than 85%, its ink and white intermingling like a wash painting; the ink is classed as dotted, streaked or clustered. Above 85% graphite the stone is "full black". The Qihakule mine at Yutian yields the most distinctive blue-flower material.
Black-qing jade黑青 · hēi qīng¶
Black to the eye yet free of graphite, coloured instead by iron-rich actinolite (FeO up to 5.69 wt%) — in truth a very dark qing jade. It transmits a qing glow under strong light, at SG about 3.00, above that of graphite black.
Gold-star black jade金星墨玉 · jīn xīng mò yù¶
Graphite black jade scattered with fine pyrite crystals, which glint like stars across an ink-dark ground.
Cui-green jade翠青玉 · cuì qīng yù¶
The eighth class newly listed in GB/T 38821-2020. Patches of vivid emerald green owed to Cr³⁺ (twin absorption bands at 450 and 650 nm), brighter than qing or spinach jade. Long known from Qinghai and Russia; found in Xinjiang at Saidikulamu, Yutian, in 2016, where its graphite inclusions mark the provenance.
Occurrence & Skin11
Seed material (alluvial pebble)籽料 · zǐ liào¶
Pebbles milled for aeons in river gravels — dragged, rolled and saltated until only the dense heart survives. They come from the middle and lower White Jade and Karakash rivers, their terraces and the palaeochannels of the piedmont fans. Its passports are the skin colour and the "sweat pores". Measured hardness averages 6.44, first among the four occurrences.
Mountain material (primary)山料 · shān liào¶
Quarried straight from the lode: large, angular blocks that have undergone no natural culling, hence the widest variation in quality and the most fissures — measured hardness averaging 5.90, last of the four. The stock of monumental carving.
Shanliushui (sub-alluvial)山流水 · shān liú shuǐ¶
Residual-slope material carried a short way from the lode and lightly water-worn: sub-angular, smoother of surface, sometimes locally skinned, and intermediate in quality between mountain and seed. The trade name means "water-borne from the mountain"; the Hanniyayilake valley on the upper White Jade River is the noted source.
Gobi material (aeolian)戈壁料 · gē bì liào¶
Slope material flushed onto the piedmont gravel plains and then sand-blasted for millennia into a rippled, satin skin, graded by the coarseness of its etching into pomelo, orange, roe and satin. Flat and sub-angular, with a measured length-to-thickness ratio averaging 3.8. The Gobi setting is unique to Xinjiang — no other source yields such material.
Glacial material冰碛料 · bīng qì liào¶
Jade plucked and carried by high glaciers and dumped at the terminal moraine, its surface bearing the characteristic scour of ice. A special case of residual-slope deposit; the Heishan (Agejugai) glacier at Hotan is the most famous, and a sixty-tonne qing boulder was once found below the north-slope glacier of Muztagh.
Skin colour皮色 · pí sè¶
The secondary crust a river pebble acquires as iron and manganese seep into its surface fissures over long burial. The varieties are many — autumn-pear, jujube-red, gold-flecked, tiger and lamp-soot skins. True skin fades outward from within the fissures in natural gradation; dye floats on the surface, pools in hollows and ends in a hard line.
"Sweat pores"汗毛孔 · hàn máo kǒng¶
The fine natural pitting on a river pebble's surface, named for its likeness to skin pores and formed as softer minerals spall away under water-borne abrasion. Genuine pores vary in size and spacing; machine-tumbled fakes show uniform pitting. Magnified examination of them is the first test of a seed pebble's authenticity.
Re-dyed skin二上色 · èr shàng sè¶
Artificial colour laid over a genuine pebble whose own skin is unimpressive — the most deceptive of frauds, since the stone itself is real. Detection demands examining the whole piece for traces of grinding and dye, the giveaways being colour floating in fissures and ending in an abrupt boundary.
Tumbled (faked) pebble滚料 · gǔn liào¶
Cheap lode material rounded in a tumbler and dyed to imitate skin, then sold as seed. It betrays itself by parallel polishing marks on the rounded faces, uniform pitting, surface-floating colour, and the want of a true pebble's streamlined form.
Etch skin蚀皮 · shí pí¶
The rippled, polished crust that wind-borne sand grinds onto Gobi material over centuries. Natural etching varies from face to face and even across one face, with fine healed cracks and silt lodged in the hollows; sand-blasted imitations show even pitting and no silt at all.
Secondary colour次生色 · cì shēng sè¶
Colour acquired after the stone leaves its lode, as foreign matter seeps in during weathering, transport and burial — as opposed to primary colour formed at the time of mineralisation. Nephrite's sugar tint and the skins of river pebbles are both secondary.
Texture & Flaws16
Unctuousness油性 · yóu xìng¶
Nephrite's central aesthetic measure, with two aspects: the visual greasy lustre — a soft, unglaring reflection — and the tactile slip-and-drag of the surface, like congealed fat, faintly clinging to the hand. It depends on composition, grain fineness, fibre arrangement and polish. This is what nine thousand years of Chinese writing means by "warm and moist".
Fat content (of feel)脂份 · zhī fèn¶
A trade term for how fully a stone carries the quality of rendered fat — akin to unctuousness but weighted toward density and heaviness of feel. A stone rich in it reads like fat just set; one poor in it looks white but "watery" and thin.
Maturity老熟 · lǎo shú¶
A trade term for the whole state of a stone that is dense, evenly fine-grained, rich in fat and settled in colour — ripe, as a fruit is ripe. Its opposite is "green" or raw. Maturity weighs heavily in the valuation of seed pebbles.
"Structureless"无结构 · wú jié gòu¶
A trade term for jade so fine that no grain or fibre shows even under strong raking light. Nothing is truly without structure: the stone is cryptocrystalline, its grains under 0.01 mm. One of the conditions of mutton-fat rank.
Felted interwoven texture毛毡状交织结构 · máo zhān zhuàng¶
The microscopic fabric in which tremolite fibres grow without preferred orientation, interlocking and threading through one another so that no grain boundary can be made out. It is the root of nephrite's unmatched toughness: the finer the fibres, the more complex their interweaving and the tighter their interlock, the tougher the stone.
"Bone" (calcified patch)僵 · jiāng¶
An opaque white or greyish patch of stony, loosely knit material within the jade — relict carbonate and kindred minerals left by incomplete metasomatism. Good flesh often lies along its border, whence the trade saying that the best meat is found at the edge of the bone.
Cotton棉 · mián¶
White inclusions spread through the stone in wispy, cloudy or web-like patches, formed of scattered coarse tremolite, pyroxene and metasomatic pseudomorphs; common in white and greenish-white jade, and visible only under a raking torch. A chief factor in clarity grading.
Wisp inclusions絮状物 · xù zhuàng wù¶
The formal name for "cotton". Its form differs by provenance and so helps identify origin: Xinjiang material has few, drawn out in long strands; Qinghai more; Russian material shows clots and "crab-claws"; Korean the most, often in a "rice-porridge" pattern.
Water line水线 · shuǐ xiàn¶
A slender line within the stone more translucent than the body around it, formed by local recrystallisation during mineralisation. It is a kind of stone line — healed into the matrix, with no open surface, and far less damaging than a true fissure. Qinghai material is full of them, which is its clearest identifying mark.
Stone line (healed)石纹 · shí wén¶
A line formed during mineralisation, since filled by later matter and re-consolidated: it has no open surface and is one with the matrix around it. It resembles a crack but is nothing like one in effect. Dealers habitually call cracks "stone lines" — be on guard.
Fissure / crack绺裂 · liǔ liè¶
A line along which the crystal continuity of the stone is broken, with an open surface, and gravely damaging to quality. Three causes: crustal movement after mineralisation, blasting during extraction, and collision during river transport. The Kunlun's violent tectonics make pebbles especially crack-prone — "nine seeds in ten are cracked". Five grades run from hairline to major.
Foliation片理化 · piàn lǐ huà¶
A fabric in which late directed stress has aligned the minerals and opened parallel partings, so that the stone splits in sheets along them. Common in spinach-green lode material and one reason its measured hardness runs low. Rough should be examined carefully for it.
Dot inclusions点状物 · diǎn zhuàng wù¶
Fine specks sharply bounded against the matrix. In spinach jade the black dots are chromite (Cr₂O₃ up to 45–65%); in blue-flower black jade they are graphite; white and greenish-white jade commonly carry white and tan specks.
Cryptocrystalline隐晶质 · yǐn jīng zhì¶
A fabric so fine-grained that no individual crystal can be made out by eye or ordinary lens (grains under 0.01 mm). Nephrite is cryptocrystalline, hence its fineness; quartzite and marble imitations are visibly granular, which tells them apart at once.
Greasy lustre油脂光泽 · yóu zhī guāng zé¶
A soft reflection between vitreous and waxy, as though the surface were oiled. It is nephrite's most distinctive optical quality and its greatest advantage, graded strong, medium or weak; jadeite by contrast is vitreous.
Clarity净度 · jìng dù¶
The degree to which a stone is free of flaws. Flaws take three forms — dots, patches and wisps — in white, black, yellow or green. The fewer and the paler, the better; four ranks run from clean to impure.
Jadeite Terms21
Texture-and-water种水 · zhǒng shuǐ¶
Jadeite's first measure of quality. Zhong names the fineness of the fabric — grain size and how tightly the crystals interlock — and shui ("water", or "water head") the depth of translucency. The ladder runs glass, ice, glutinous, bean. Unlike nephrite, jadeite is prized the clearer it is.
Glass grade玻璃种 · bō li zhǒng¶
The crown of the ladder: fully transparent, its grain invisible, often showing the fluorescence and gel effects. Glass grade carrying imperial green is the rarest of all jadeite and heads the great auction lots.
Ice grade冰种 · bīng zhǒng¶
Limpid as river ice, with faint cotton wisps and a cool inner light — the body of fine jadeite. Material between ice and glutinous is called "ice-glutinous" in the trade.
Glutinous grade糯种 · nuò zhǒng¶
Semi-translucent like glutinous rice broth — mellow and substantial rather than clear. The mainstay of the market and its best value for money.
Bean grade豆种 · dòu zhǒng¶
Coarse enough that the grains stand out like split beans, faintly translucent to opaque. The commonest of all jadeite — "nine green stones in ten are bean", as the saying goes.
Fluorescence effect起荧 · qǐ yíng¶
The soft, misty halo that plays across glass and high-ice jadeite as a domed surface is turned in the light, like sheen on still water. Not true fluorescence but refraction within an exceptionally fine, dense fabric — with the gel effect, a mark of the highest grades.
Gel effect起胶 · qǐ jiāo¶
The congealed, gel-like glow a stone gives when turned, as though its interior were half-set jelly — the sign of an exceptionally even, tightly knit crystal fabric, and of "old" texture.
Imperial green帝王绿 · dì wáng lǜ¶
The summit of jadeite colour: a deep, regal green with a whisper of blue, owed to Cr³⁺, and needing ice grade or better to show its worth. Green is judged by four words — deep, bright, true, even.
Apple green阳绿 · yáng lǜ¶
The bright, lively green of new leaves — less saturated than imperial green but quicker and more buoyant in effect. Also called apple green.
"Spring" (lavender)春 · chūn¶
The trade's word for lavender jadeite — pale violet as first wisteria, in pinkish, aubergine and bluish casts. A stone carrying both violet and green is "spring with colour", and highly prized.
Fei and Cui翡 / 翠 · fěi / cuì¶
The two characters originally named the red-feathered and green-feathered kingfishers. In the trade, fei denotes the warm secondary colours — red, yellow, brown, mostly from the skin and mist layer — and cui denotes green. Together they name the stone.
Omphacite black墨翠 · mò cuì¶
Jadeite dominated by omphacite: ink-black in the hand, yet glowing green when strong light passes through it — "the lover's shadow". Polished to a lacquer-like gloss, it is often carved with religious subjects.
Dry green干青种 · gān qīng zhǒng¶
Jadeite dominated by kosmochlor — intense in green but dry and opaque in body, whence the name. Denser than ordinary jadeite, and of modest value.
Floating flowers飘花 · piāo huā¶
Ribbons or patches of green or blue drifting through the body of the stone like waterweed. Ice grade with floating flowers is much admired, the best having an open, unforced movement.
Fu-lu-shou (tricolour)福禄寿 · fú lù shòu¶
A single stone bearing green, red and violet together — the three star-gods of blessing, rank and long life. Clear, vivid tricolour is exceedingly rare; add white and it becomes the fourfold "fu-lu-shou-xi".
Types A, B and CA 货 / B 货 / C 货 · A / B / C huò¶
Jadeite classed by treatment. Type A: natural, merely cut and polished — the only collectable grade. Type B: acid-bleached and resin-impregnated, its fabric destroyed and its lustre bound to degrade. Type C: dyed, the colour lodging in fissures. National standards require disclosure: a report reading "feicui (treated)" or "(dyed)" means B or C.
Gambling on rough赌石 · dǔ shí¶
The trade in skinned jadeite boulders whose interior no one can see until the saw falls — "one cut to ruin, one cut to riches". Buyers read the python bands, pine flowers and mist layer on the skin to guess at the colour within; the risk is extreme.
Window开窗 · kāi chuāng¶
A small flat patch ground through the skin of a boulder to glimpse the texture and colour within. What the window shows is local only and cannot settle the whole stone — which is why the gamble remains.
"Python" band蟒 · mǎng¶
A band coiling across a boulder's skin, differing in texture and colour from the crust around it, like a python wound about the stone. It often signals green beneath, and is a chief sign read when gambling on rough.
"Pine flower"松花 · sōng huā¶
Dry green or grey-green marks — dotted, threadlike or patchy — on a boulder's skin: the weathered residue of green lying beneath. Dense, concentrated pine flower usually promises good colour below.
Mist layer雾 · wù¶
The transitional layer between a boulder's skin and its flesh, weathered to white, yellow, red or black. Yellow and red mist often overlie red and yellow fei; black mist usually warns of poor material.
Craft & Workshops5
Clever-colour carving巧色 / 俏色 · qiǎo sè¶
Carving conceived around the stone's own colouring, so that a patch of foreign tint becomes exactly the thing depicted — sugar tint turned to an animal's pelt, russet skin to an autumn leaf. Already practised on the jade turtle from Fu Hao's tomb, it is the most inventive of Chinese lapidary techniques.
Retained skin留皮 · liú pí¶
Leaving part of a pebble's natural skin on the finished carving — proof of its seed origin, and material for clever-colour work. The fashion has run strong these twenty years as pebble prices rose; but skin is also left to hide flaws, and should be read with care.
Zigang plaque子冈牌 · zǐ gāng pái¶
The rectangular plaque created by Lu Zigang, the celebrated late-Ming carver of Suzhou: a picture on one face, a poem on the other, within a precise border, and signed by the maker. His signature broke new ground, joining lapidary work to calligraphy and painting; copied ever since, the name now denotes the form itself.
Qianlong work乾隆工 · qián lóng gōng¶
The standard and style of the palace workshops under the Qianlong emperor. With the Hotan tribute road secured and the finest craftsmen gathered at the Imperial Household Department, line grew vigorous, grounds even, polish warm, and no labour was spared. The five-tonne jade mountain "Yu the Great Taming the Waters", a decade in the carving, is its apex.
Hindustan style痕都斯坦工 · hén dū sī tǎn gōng¶
The thin-walled jade technique that reached Qing China from northern India and Central Asia — vessels ground "thin as paper", shaped as leaves and flowers and inlaid with gold and gems. The Qianlong emperor prized them above measure, inscribing more than eighty poems upon them, and had the court copy the style.
Ritual Forms11
Bi disc璧 · bì¶
A flat disc pierced at the centre, the bore narrower than the ring around it. The Rites of Zhou appoints "the azure bi to honour Heaven", its circle the dome of the sky — first of the six implements. Already abundant in the Liangzhu culture; the Heshibi was of this form.
Cong tube琮 · cóng¶
A tube square without and round within, bored end to end. The Rites of Zhou appoints "the yellow cong to honour Earth". It is the signature implement of the Liangzhu culture: the "Cong King" in the Zhejiang Museum weighs 6.5 kilograms, its man-and-beast emblem engraved finer than a hair.
The six ritual implements六器 · liù qì¶
From the Rites of Zhou: "With jade are made the six implements, to honour Heaven, Earth and the four quarters — the azure bi for Heaven, the yellow cong for Earth, the green gui for the East, the red zhang for the South, the white hu for the West, the black huang for the North." The charter of the Chinese jade liturgy.
Gui tablet圭 · guī¶
A long tablet, pointed above and square below: "the green gui honours the East". It served also as a token of audience and investiture, the Son of Heaven holding the great gui and each rank of noble its own — whence the phrase that gui and zhang need no intermediary.
Zhang璋 · zhāng¶
An implement shaped as half a gui: "the red zhang honours the South". The Book of Songs has a newborn boy "given a zhang to play with", and ever after "playing with the zhang" has meant the birth of a son.
Hu tiger token琥 · hǔ¶
A tiger-form jade: "the white hu honours the West". The West governs autumn and arms, and the tiger is chief of fierce beasts — whence the pairing. Some served as military tallies.
Huang arc璜 · huáng¶
An arc, half a bi disc: "the black huang honours the North". It served too as a main member of pendant sets, pierced at both ends for cords and hung with heng bars and chongya clappers.
Jue (slit ring)玦 · jué¶
A ring broken by a single slit, most often worn in the ear. Those from Xinglongwa in Inner Mongolia are some eight thousand years old and carry China's jade record back to that date. The word puns on "decision", and a jue was anciently sent to signal a final break.
Pendant set组佩 · zǔ pèi¶
A set of huang arcs, heng bars, ju and yu beads and chongya clappers strung on silk and hung at the waist. In walking they chimed and so governed the pace — which is why the Book of Rites says the gentleman does not part with his jade without cause: the pendants marked both his bearing and his rank.
Jade burial suit玉衣 · yù yī¶
The shroud of Han emperors and great nobles, of jade plaques sewn with gold, silver or bronze wire according to rank. That of Prince Liu Sheng of Zhongshan joins 2,498 plaques with some 1,100 grams of gold thread. It rests on the Han belief that jade preserves the body incorrupt.
Funerary jades玉琀与九窍塞 · yù hán / jiǔ qiào sāi¶
The Han furniture of the tomb. The han was laid in the mouth, usually carved as a cicada for its promise of rebirth; the nine-orifice plugs sealed eyes, ears, nostrils, mouth and the lower openings against the escape of vital essence; and the wo, commonly a pig, was placed in each hand.
Testing & Standards10
Refractive index折射率 · zhé shè lǜ¶
The ratio of light's speed in vacuum to its speed in the stone — the most basic constant in gem testing. Nephrite spot-reads about 1.60–1.62 (averaging 1.61) and jadeite 1.666–1.680; quartzite reads 1.54, chalcedony 1.53–1.54, serpentine 1.56–1.57 and albite jade 1.52–1.53, all clearly below nephrite.
Specific gravity相对密度 · xiāng duì mì dù¶
The mass of a stone against that of an equal volume of water at four degrees, measured by hydrostatic weighing. Nephrite measures 2.86–3.06 (averaging 2.96), rising with iron: white 2.94, qing 2.97, spinach 3.00, black-bi 3.02. Jadeite runs 3.30–3.36, so an equal volume of it hefts noticeably heavier.
Mohs hardness摩氏硬度 · mó shì yìng dù¶
A relative scale set by the scratching order of ten standard minerals, from talc at 1 to diamond at 10. Nephrite is 6–6.5, jadeite 6.5–7. Useful references: a fingernail about 2.5, a copper coin 3.5, a pocket knife 5.5, window glass 6, a steel file 6.5 — a stone a knife will not mark but that marks glass may be jade.
Toughness韧性 · rèn xìng¶
Resistance to impact and tearing — the opposite of brittleness, and not to be confused with hardness. Nephrite rates 9 in relative toughness, first among all jades, behind only carbonado at 10; jadeite and corundum rate 8. Measured Xinjiang nephrite averages 397.96 MPa in compression and 42.04 MPa in tension, far above common rocks.
Enhancement vs treatment优化与处理 · yōu huà yǔ chǔ lǐ¶
Two concepts the national standards keep apart. Enhancement means traditional, widely accepted methods that bring out a stone's latent beauty — waxing, for instance — and need not be declared. Treatment means non-traditional, unaccepted methods such as acid-bleaching and impregnation, dyeing or irradiation, and must always be declared, as in "feicui (treated)". This is the floor of consumer protection.
Gemmological certificate鉴定证书 · jiàn dìng zhèng shū¶
The report issued by an accredited laboratory. Three things to check: the accreditation marks (CMA, CNAS, ILAC); that the report number and photograph match the stone in hand; and the name itself — "Hetian jade" states no origin, while "feicui (treated)" or "(dyed)" means Type B or C. Most laboratories allow the number to be verified online.
GB/T 38821-2020GB/T 38821-2020¶
The national standard "Hetian Jade — Testing and Classification", the governing authority on nephrite classification. It fixes eight colour classes — white, greenish-white, qing, spinach-green, yellow, sugar, black and cui-green — and establishes that "Hetian jade" names tremolite jade generally, with no geographic meaning.
GB/T 16552GB/T 16552¶
The national standard "Gems — Nomenclature", the charter of gem naming in China. It establishes the legal names "Hetian jade" and "feicui" and lays down the compulsory disclosure of treated material, working in tandem with GB/T 16553, "Gems — Testing".
Provenance determination产地鉴别 · chǎn dì jiàn bié¶
Because the five great sources share one genesis and differ almost not at all in physical data, routine instruments cannot separate them; in practice about seventy percent can be judged by a trained eye, the rest requiring trace-element, rare-earth and isotope analysis. Certificates state no origin, yet the market pays a large origin premium — which makes this the most demanding judgement of all.
Telling look-alikes apart相似玉石鉴别 · xiāng sì yù shí¶
Seven stones commonly pass for nephrite: quartzite, chalcedony, serpentine, marble, albite, brucite and wollastonite jade. Refractive index and specific gravity settle the matter; by eye, judge the fabric (nephrite cryptocrystalline, the imitations visibly granular), the lustre (greasy against vitreous), the fracture (splintery against granular or conchoidal) and the weight in the hand.