{"id":15,"date":"2026-04-12T08:30:00","date_gmt":"2026-04-12T08:30:00","guid":{"rendered":"https:\/\/ckystones.com\/du-reve-a-la-realite-explorer-la-magie-des-pierres-precieuses\/"},"modified":"2025-03-24T03:37:57","modified_gmt":"2025-03-24T03:37:57","slug":"le-jade-importance-et-modes-didentification","status":"publish","type":"post","link":"https:\/\/ckystones.com\/en\/le-jade-importance-et-modes-didentification\/","title":{"rendered":"Jade: its importance and methods of identification"},"content":{"rendered":"<p style=\"text-align: left;\"><a href=\"https:\/\/www.gia.edu\/jade-description\" rel=\"nofollow noopener\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33841\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/41235c8_10789-1e57q5.q4v6hnz5mi-400x300.avif\" alt=\"\" width=\"281\" height=\"211\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/41235c8_10789-1e57q5.q4v6hnz5mi-400x300.avif 400w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/41235c8_10789-1e57q5.q4v6hnz5mi-430x322.avif 430w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/41235c8_10789-1e57q5.q4v6hnz5mi-700x525.avif 700w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/41235c8_10789-1e57q5.q4v6hnz5mi-150x112.avif 150w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/41235c8_10789-1e57q5.q4v6hnz5mi.avif 750w\" sizes=\"auto, (max-width: 281px) 100vw, 281px\" \/><\/a> <img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33836 alignright\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/unnamed.png\" alt=\"\" width=\"273\" height=\"204\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/unnamed.png 273w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/unnamed-150x112.png 150w\" sizes=\"auto, (max-width: 273px) 100vw, 273px\" \/><\/p>\n<p style=\"text-align: center;\">Fran\u00e7oise Li-de Vries \u2014 December 2017 \u2014 Diploma project \u2014 Jade: its importance and methods of identification\u00a0<\/p>\n<p style=\"text-align: left;\">CONTENTS<\/p>\n<p style=\"text-align: left;\">Introduction<\/p>\n<p style=\"text-align: left;\">Part One: the definition and importance of jade<\/p>\n<ul>\n<li style=\"text-align: left;\">Historical background<\/li>\n<li style=\"text-align: left;\">Mineralogical characteristics of jadeite jade and nephrite jade<\/li>\n<li style=\"text-align: left;\">Jade quality criteria \u2014 Sources<\/li>\n<\/ul>\n<p>Part Two: methods of identifying jade<\/p>\n<ul>\n<li>Classification of Type A, B and C jades<\/li>\n<li>Conventional identification tests<\/li>\n<li>Laboratory tests<\/li>\n<\/ul>\n<p>Conclusion<\/p>\n<p><strong>Introduction\u00a0<\/strong><\/p>\n<p>Virtually unknown in Europe until the nineteenth century, jade was often confused with the quartz varieties jasper and chalcedony. The Spanish, who brought it from the Americas, called it \u2018piedra de ijada\u2019 (\u2018kidney stone\u2019 or \u2018flank stone\u2019). The French term derived from this became \u2018pierre de l'\u00e9jade\u2019, then, through a change in pronunciation, jade, which first appeared in the Dictionnaire g\u00e9n\u00e9ral in 1667. The earliest jade objects date from the Neolithic period, around 5000\u20137000 BC.<\/p>\n<p>In China and also in Korea, jade symbolises much more than a rare gem: it represents power, high social status and virtue. Jade, the \u2018stone of Heaven\u2019, was also used to connect heaven and earth through funerary objects such as urns or small sculptures placed beside the dead to ward off evil and immortalise their souls. The pierced discs, or bi, represent heaven.<\/p>\n<p>The first part of this work addresses the definition and importance of jade, its historical background, mineralogical characteristics, quality criteria and, finally, its sources. We will not discuss the jade of the M\u0101ori peoples here, although it is essential to their culture. A second part will detail methods of identifying jade, including the classification of Types A, B and C and conventional and laboratory identification tests.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33840 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/unnamed-1.png\" alt=\"\" width=\"179\" height=\"233\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/unnamed-1.png 179w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/unnamed-1-150x195.png 150w\" sizes=\"auto, (max-width: 179px) 100vw, 179px\" \/><\/p>\n<p style=\"text-align: center;\"><em>Crown, Silla kingdom, second half of 5th century, gold and jade, excavated from the north mound of Hwangnam Daechong Tomb, 10 3\/4\u2033 \/ 27.3 cm high (Gyeongju National Museum, Korea, National Treasure 191 <\/em><\/p>\n<p><strong>JADE TECHNICAL DATA<\/strong><\/p>\n<p>JADEITE JADE<\/p>\n<p>Group \/ family: Pyroxene Chemical class: Silicate Chemical formula: Na(Al,Fe3+)Si2O6 Composition: Sodium, aluminium and iron silicate Crystal system: Monoclinic Optical character: B+ Hardness: 7 Specific gravity: 3.30 to 3.36 Refractive index: 1.650 to 1.666 Birefringence: 0.010 to 0.016 Colour: Transparency: Rarity, rough: Rarity, cut:<\/p>\n<p>NEPHRITE JADE<\/p>\n<p>Group \/ family: Amphibole Chemical class: Silicate Chemical formula: Ca2(Mg,Fe2+)5Si8O22(OH)2 Composition: Calcium, magnesium and iron hydroxyl silicate Crystal system: Monoclinic Optical character: B- Hardness: 6.5 Specific gravity: 2.95 to 3.10 Refractive index: 1.610 to 1.660 Birefringence: 0.024 to 0.027 Colour: Transparency: Rarity, rough: Rarity, cut: (Gemmo.eu)<\/p>\n<p><strong>Part One: defining jade <\/strong><\/p>\n<p>Historical background<\/p>\n<p>In Chinese, jade, yu, \u7389, means \u2018beautiful, precious, treasure\u2019. The Chinese fascination with jade stems from the rarity and great durability \u2014 very high toughness \u2014 of this mineral, which symbolises both spiritual and temporal power. In his description of jade, Confucius (551 BC\u2013479 BC) already gave the physical characteristics still observed today: \u2018Jade is soft and pleasant\u2026 it has a fine texture but is strong\u2026 although it has edges and corners, it is not sharp\u2026\u2019<\/p>\n<p>\u2018Although jade is graceful, its imperfections are also apparent\u2026 Furthermore, the colour of jade can be seen from every angle.\u2019 Jadeite jade, with its extensive range of colours, is used in jewellery, whereas nephrite jade is more commonly found in decorative objects, sculptures or weapons. The distinction between jadeite jade and nephrite jade was established in 1863 by Augustin-Alexis Damour.<\/p>\n<p>In January 1863, he presented a chemical analysis of the two types of jade to the Acad\u00e9mie des Sciences and reached the following conclusion: \u2018From what has just been set out, I believe green jade should be classified as a separate species, attached to the Wernerite family. I propose to give it the name Jadeite to distinguish it from white jade, which remains within the Amphibole family.\u2019 White jade corresponds to nephrite jade, as found in \u2018vases, cups, dagger handles, bracelets, etc.\u2019 and \u2018is attached to the Amphibole family and particularly to the species known as tremolite.\u2019<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-33842 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-300x300.jpg\" alt=\"\" width=\"208\" height=\"208\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-300x300.jpg 300w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-150x150.jpg 150w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-768x768.jpg 768w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-400x400.jpg 400w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-600x600.jpg 600w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-430x430.jpg 430w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131-700x700.jpg 700w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/109135131.jpg 800w\" sizes=\"auto, (max-width: 208px) 100vw, 208px\" \/><em>Ancient bi jade from the Neolithic period (Christie's) <\/em><\/p>\n<p>Mineralogical characteristics of jade. Jadeite jade is a sodium and aluminium silicate: NaAl(SiO 3) 2, and nephrite jade is a hydroxyl silicate of calcium and magnesium or iron: Ca2 (Mg, Fe) 5 (OH, FSi4011) 2. Although it is established that jadeite belongs to the pyroxene group and nephrite to the amphibole group, points of confusion can arise in a strict analysis of the two types of gem.<\/p>\n<p>Nephrite combines two distinct amphiboles. Actinolite, a calcium and ferrous magnesium silicate, forms the fibrous nephrite type with tremolite, a calcium and magnesium silicate. Nephrite jade is therefore not classified as a mineral species but as a variety of actinolite\u2013tremolite. Jadeite jade has a complex chemical composition. As defined by Augustin Damour, jadeite jade is a mineral separate and distinct from nephrite: a sodium and aluminium silicate, NaAl(SiO3) 2.<\/p>\n<p>Jadeite is structurally close to other minerals in the pyroxene group and sometimes contains high concentrations of diopside or acmite. Such specimens will nevertheless be described as jadeite if their gemmological properties are not significantly altered: refractive index, specific gravity, optical spectrum and hardness. Where the gemmological data change beyond the levels compatible with the designation \u2018jadeite\u2019, the material is called \u2018diopside-jadeite\u2019.<\/p>\n<p>The structure of jadeite and nephrite materials is also decisive in distinguishing them. Although both gems must have a hard, fine-grained and compact structure \u2014 hence their great toughness \u2014 if the fibres are parallel rather than interlocked, the material cannot be nephrite but is jadeite.<\/p>\n<p><strong>Jade quality criteria<\/strong><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-33843 size-medium aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/couleurs-du-jade-e1742792618473-337x300.avif\" alt=\"\" width=\"337\" height=\"300\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/couleurs-du-jade-e1742792618473-337x300.avif 337w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/couleurs-du-jade-e1742792618473-430x382.avif 430w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/couleurs-du-jade-e1742792618473-150x133.avif 150w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/couleurs-du-jade-e1742792618473.avif 597w\" sizes=\"auto, (max-width: 337px) 100vw, 337px\" \/><\/p>\n<p style=\"text-align: center;\"><em> (GIA) <\/em><\/p>\n<p><strong>Colour <\/strong><\/p>\n<ul>\n<li>Green is jade's best-known colour. However, it also occurs in orange-red, black, lavender and bluish shades. Imperial jade, whose colour and transparency are close to those of emerald, is the rarest and most imitated. Trace elements cause colour in jade: green, for example, comes from chromium (Cr), and yellow and yellow-green from iron (Fe). Lavender colour is attributed to manganese (Mn).<\/li>\n<li>Nephrite does not occur in the same shades as jadeite: its colours range from light green to very dark green, with shades of yellow, brown, grey (\u2018chicken bone\u2019), white (\u2018mutton fat\u2019 jade) and black. Iron produces brown, yellow and green hues, although green may also contain traces of chromium. White and grey nephrite jades have very little iron compared with green shades.<\/li>\n<li>Jade's transparency ranges from opaque to translucent or semi-transparent, the latter representing the rarest quality. For exceptional gems, a \u2018see-through\u2019 test can be performed.<\/li>\n<\/ul>\n<p>Its texture can be described as coarse-grained, medium-grained or fine-grained.<\/p>\n<p>-Coarse-grained: crystals visible to the naked eye are larger than 2 mm; the material is opaque.<\/p>\n<p>-Medium-grained: crystals visible to the naked eye measure between 1 and 2 mm; the material is opaque to translucent.<\/p>\n<p>-Fine-grained: crystals visible to the naked eye measure between 1 mm and 0.5 mm; the material is translucent to transparent. -Cryptocrystalline structure: the crystals measure less than 1 mm; the jade is almost transparent.<\/p>\n<ul>\n<li>Cut is also crucial: the finest jadeite jades are cut into cabochons or beads. In terms of measurement, jade is usually measured in <a href=\"https:\/\/ckystones.com\/wp-admin\/post.php?post=34008&amp;action=edit\">millimetres.<\/a><\/li>\n<\/ul>\n<p style=\"text-align: center;\"><a href=\"https:\/\/ckystones.com\/wp-admin\/post.php?post=34008&amp;action=edit\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-33844\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement.jpg\" alt=\"\" width=\"275\" height=\"183\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement.jpg 275w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-150x100.jpg 150w\" sizes=\"auto, (max-width: 275px) 100vw, 275px\" \/><\/a><\/p>\n<p style=\"text-align: center;\">A)<\/p>\n<p><strong>Sources <\/strong><\/p>\n<p>Jadeite jade is characterised by its extreme rarity. It is found in Guatemala near the Motagua Valley; in Niigata Prefecture in Japan; at Itmurundy in Kazakhstan; in Russia, mainly in the Polar Urals; and in California in the United States, in serpentine veins at New Indria. A deposit was discovered in Italy's western Alps in 2002. The most important deposit, however, is the \u2018Jade Tract\u2019, or \u2018Jade Route\u2019, in Myanmar's Kachin State.<\/p>\n<p>The principal deposit is at Hpakan. Jadeite jade production in Myanmar is steadily increasing in response to the exponential demand from the Chinese market. However, Western nations' recent consideration of environmental and ethical issues associated with jade extraction has led to sanctions against the Burmese government. China did not participate in these international sanctions. The number of licences authorising mining therefore appears to be stagnating. Nephrite jade deposits are located in China, Russia, New Zealand and Canada.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-33847 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-1.jpg\" alt=\"\" width=\"368\" height=\"243\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-1.jpg 276w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-1-150x99.jpg 150w\" sizes=\"auto, (max-width: 368px) 100vw, 368px\" \/><\/p>\n<p><strong>Part Two: methods of identifying jade <\/strong><\/p>\n<p>The classification of the different types of jade was established in Hong Kong for the jade trade in the 1980s. It applies only to jadeite jade, fei cui. The \u2018Standard methods for testing fei cui\u2019 (2006) define four types of jadeite jade:<\/p>\n<p>1- Type A: natural jadeite jade that has not been treated. The surface may have a wax coating to improve its lustre, but this is not regarded as a treatment.<\/p>\n<p>2- Type B: jadeite jade impregnated with resin to improve transparency and chemically treated, most often by bleaching. The resulting lustre gradually disappears over time. Type B jades do not withstand heat or pressure.<\/p>\n<p>3- Type C: jadeite jade that has been coloured with a dye. This treatment is not durable over time.<\/p>\n<p>4- Dyed Type B+C: jadeite jade treated with chemical bleaching agents, resin-impregnated and dyed. Note also the concept of Type D jade, which appeared later and is not cited by official gemmological bodies. It is an assemblage of natural jadeite and a doublet. This category is nevertheless very uncommon.<\/p>\n<p><strong> Conventional identification tests<\/strong><\/p>\n<p>Conventional tests make it possible to distinguish jadeite jade from its imitations and to detect the different treatments applied to it, whether dyeing or impregnation.<\/p>\n<p>Conventional tests:<\/p>\n<p>10\u00d7 loupe<img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33851\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-3.jpg\" alt=\"\" width=\"184\" height=\"138\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-3.jpg 259w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-3-150x112.jpg 150w\" sizes=\"auto, (max-width: 184px) 100vw, 184px\" \/><\/p>\n<p>Microscope in reflected and transmitted light<img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33854\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-6.jpg\" alt=\"\" width=\"165\" height=\"165\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-6.jpg 225w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-6-150x150.jpg 150w\" sizes=\"auto, (max-width: 165px) 100vw, 165px\" \/><\/p>\n<p>The polariscope<img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33853\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-5.jpg\" alt=\"\" width=\"141\" height=\"141\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-5.jpg 225w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-5-150x150.jpg 150w\" sizes=\"auto, (max-width: 141px) 100vw, 141px\" \/><\/p>\n<p>The refractometer<img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33850\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-2.jpg\" alt=\"\" width=\"154\" height=\"154\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-2.jpg 225w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-2-150x150.jpg 150w\" sizes=\"auto, (max-width: 154px) 100vw, 154px\" \/><\/p>\n<p>Specific gravity<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-33849\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/images.jpg\" alt=\"\" width=\"208\" height=\"143\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/images.jpg 271w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/images-150x103.jpg 150w\" sizes=\"auto, (max-width: 208px) 100vw, 208px\" \/><\/p>\n<p>The UV cabinet<img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33855\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-7.jpg\" alt=\"\" width=\"176\" height=\"176\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-7.jpg 225w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-7-150x150.jpg 150w\" sizes=\"auto, (max-width: 176px) 100vw, 176px\" \/><\/p>\n<p>The Chelsea filter<img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-33848\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/images-1.jpg\" alt=\"\" width=\"160\" height=\"120\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/images-1.jpg 259w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/images-1-150x112.jpg 150w\" sizes=\"auto, (max-width: 160px) 100vw, 160px\" \/><\/p>\n<p><strong>Observation with the naked eye<\/strong><\/p>\n<p>The stone's overall appearance, colour, lustre and transparency can be assessed. Medium- and coarse-grained structures are visible.<\/p>\n<p><strong>10X loupe<\/strong><\/p>\n<p>This instrument allows observation of a specimen's lustre, colour and cut and, to a lesser extent, its more or less finely grained polycrystalline structure.<\/p>\n<p><strong>Microscopic observation in reflected and transmitted light<\/strong><\/p>\n<p>Under the microscope, reflected light allows closer examination of the surface condition and colour and can provide a fairly precise indication of whether the jade is Type A, B or C. For example, an \u2018orange-peel\u2019, \u2018fly-wing\u2019, \u2018sand-hole\u2019 or \u2018spider-web\u2019 surface may be observed. If the stone is sufficiently translucent, transmitted light reveals the quality of the specimen's internal structure, particularly fine-grained structure.<\/p>\n<p><strong>Polariscope<\/strong><\/p>\n<p>The stone remains illuminated throughout a 360\u00b0 rotation because it is polycrystalline.<\/p>\n<p><strong>Refractometer<\/strong>\u00a0<\/p>\n<p>The refractive index ranges from 1.64 to 1.68 for jadeite jade and is 1.62 for nephrite jade. Most specimens are cut as cabochons or beads, so a spot reading will usually be taken. For other cuts, care should be taken to select the best-polished face available. There is generally no birefringence reading because the gem is polycrystalline.<\/p>\n<p><strong>Specific gravity<\/strong><\/p>\n<p>Jadeite jade has a specific gravity of 3.30 to 3.36; nephrite jade ranges from 2.81 to 3.1. Specific gravity can be measured using a hydrostatic balance and the formula D = Mair \/ (Mair \u2013 Mwater). It can also be determined using a heavy liquid with a density comparable to that of the specimen being tested. For jadeite jade, methylene iodide may be used, with a density of 3.30 to 3.40 or above.<\/p>\n<p>For nephrite jade, diluted or pure bromoform comes closest to its specific gravity, with values between 2.85 and 3.30. The specimen is immersed in the liquid until it reaches a point of suspension between floating and sinking slowly. Although less precise than hydrostatic weighing, this method allows specific gravities to be compared in the field, several specimens to be tested simultaneously, and large specimens to be assessed.<\/p>\n<p><strong>Chelsea filter<\/strong><\/p>\n<p>These results are not reliable on their own but can complement other observations. -Type A green jadeite: dull green, or red if it contains chromium. Chromium-bearing imperial jade also appears red. \u2013 Type C dyed green jadeite: sometimes pink or red.<\/p>\n<p><strong>UV cabinet<\/strong><\/p>\n<p>Long-wave UV (365 nm). Green jades; lavender; white. Light green: inert to dark red; reddish-brown for untreated stones; weak yellow; weak white. Dark-coloured jades: generally inert. Type B jadeite: often blue fluorescence under long-wave UV. Lavender colour may appear orange.<\/p>\n<p>Short-wave UV (264 nm): the same observations as for long-wave UV, but weaker.<\/p>\n<p><strong>Handheld diffraction-grating spectroscope<\/strong><\/p>\n<p>A band is generally observed in the blue-violet at 437 nanometres (nm), indicating the presence of Fe 3+ (Fig. 2).<\/p>\n<p>-Jades in various pale colours: a fine line in the blue-violet.<\/p>\n<p>-\u2018Non-green\u2019 translucent jades: absorption lines at 437 and 690 nm.<\/p>\n<p>\u2013 Green jades: one or two lines in the red caused by chromium, and sometimes additional fine lines in the blue, which may be difficult to observe because of strong absorption.<\/p>\n<p>-Imperial-type jadeite: a line at 437 nm and three fine absorption lines in the red at 630, 660 and 690 nm (Fig. 2), indicating the presence of chromium.<\/p>\n<p>-Dark green jadeite: absorption lines at 630, 660 and 690 nm.<\/p>\n<p>-Medium-green jadeite coloured by chromium: the same.<\/p>\n<p>-Type C dyed jadeite, Fig. 1, Fig. 2: a thick absorption line between 630 and 690 nm.<\/p>\n<div id=\"attachment_33857\" style=\"width: 210px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-33857\" class=\"wp-image-33857 size-full\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-8.jpg\" alt=\"Figure 1\" width=\"200\" height=\"100\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-8.jpg 200w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-8-150x75.jpg 150w\" sizes=\"auto, (max-width: 200px) 100vw, 200px\" \/><p id=\"caption-attachment-33857\" class=\"wp-caption-text\"><em>Diffraction spectroscope<\/em><\/p><\/div>\n<div id=\"attachment_33856\" style=\"width: 210px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-33856\" class=\"wp-image-33856 size-full\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/sptobs_jadeite_vertepale.jpg\" alt=\"Figure 2\" width=\"200\" height=\"100\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/sptobs_jadeite_vertepale.jpg 200w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/sptobs_jadeite_vertepale-150x75.jpg 150w\" sizes=\"auto, (max-width: 200px) 100vw, 200px\" \/><p id=\"caption-attachment-33856\" class=\"wp-caption-text\"><em>Calcite spectroscope<\/em><\/p><\/div>\n<p><strong>Laboratory tests<\/strong><\/p>\n<p>While Types A and C jade are relatively easy to identify using conventional identification tests, the same cannot be said of Type B jade, which requires laboratory tests.<\/p>\n<p><strong>Fourier-transform infrared spectrometer (FTIR)<\/strong><\/p>\n<p>Infrared spectroscopy measures the absorption of materials in the part of the electromagnetic spectrum occupied by infrared radiation. This region is useful because of absorption by vibrations arising from the molecular and structural components of materials. It is a particularly useful instrument for detecting polymer-resin impregnation in Type B jadeite.<\/p>\n<p>An FTIR spectrometer obtains spectral data from a beam containing a combination of many frequencies of light, and measures the specimen's absorption. The beam is produced by a broadband light source containing the full spectrum of wavelengths to be measured. The operation is repeated many times to obtain as many combinations as possible. Once all the data have been acquired, they are processed computationally to calculate absorption at each wavelength in reverse. This process requires an algorithm: the Fourier transform.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33859 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-9.jpg\" alt=\"\" width=\"277\" height=\"182\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-9.jpg 277w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-9-150x99.jpg 150w\" sizes=\"auto, (max-width: 277px) 100vw, 277px\" \/><\/p>\n<p style=\"text-align: center;\"><em> Fourier-transform infrared spectrometer (Lotus Gemology) <\/em><\/p>\n<p>Interpreting the results. A group of very intense peaks \u2014 strong absorption \u2014 between 2850 cm-1 and 3100 cm-1 demonstrates polymer-resin impregnation.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33864 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement.png\" alt=\"\" width=\"276\" height=\"183\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement.png 276w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-150x99.png 150w\" sizes=\"auto, (max-width: 276px) 100vw, 276px\" \/><\/p>\n<p style=\"text-align: center;\"><em> (Gemmoraman.com) <\/em><\/p>\n<p><strong>The Raman spectrometer<\/strong><\/p>\n<p>The principle is based on a material absorbing a very high-energy beam and re-emitting a small amount of energy at another level. Among other uses, it identifies substances such as dyes, waxes and oils. Raman spectroscopy distinguishes the different types of jade \u2014 jadeite and nephrite (Fig. 1) \u2014 and treated Types B and C (Fig. 2). Nephrite jade shows a peak around 3680. Type A Fei Cui jadeite jade has no peaks above 1100 cm-1. Type B jadeite jade shows a series of peaks between 3000 cm-1 and 1610 cm-1.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33860 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-10.jpg\" alt=\"\" width=\"278\" height=\"182\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-10.jpg 278w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-10-150x98.jpg 150w\" sizes=\"auto, (max-width: 278px) 100vw, 278px\" \/><\/p>\n<p style=\"text-align: center;\"><em>Fig. 1: Raman spectra of jadeite jade and nephrite jade (gemmoraman.com)<\/em><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33858 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-1.png\" alt=\"\" width=\"278\" height=\"182\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-1.png 278w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-1-150x98.png 150w\" sizes=\"auto, (max-width: 278px) 100vw, 278px\" \/><\/p>\n<p style=\"text-align: center;\"><em>Fig. 2: Raman spectra of Type A and Type B Fei Cui jadeite (gemmoraman.com) <\/em><\/p>\n<p style=\"text-align: left;\"><strong>DiamondView <\/strong><\/p>\n<p style=\"text-align: left;\">Fourier-transform infrared and Raman spectroscopy are the two preferred laboratory methods for identifying impregnation-treated jade. However, recent tests have demonstrated the reliability of the DiamondView instrument.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33861 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-11.jpg\" alt=\"\" width=\"279\" height=\"181\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-11.jpg 279w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-11-150x97.jpg 150w\" sizes=\"auto, (max-width: 279px) 100vw, 279px\" \/><\/p>\n<p style=\"text-align: center;\"><em>DiamondView (LFG)<\/em><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33862 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-12.jpg\" alt=\"\" width=\"260\" height=\"194\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-12.jpg 260w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-12-150x112.jpg 150w\" sizes=\"auto, (max-width: 260px) 100vw, 260px\" \/><\/p>\n<p style=\"text-align: center;\"><em>DiamondView imaging of impregnated jadeite jade specimens (Gem Lab) <\/em><\/p>\n<p style=\"text-align: center;\">Under white light, both samples display a \u2018cobweb\u2019 structure. The UV light produced by the DiamondView highlights this structure with strong blue fluorescence, clearly indicating impregnation treatment in both specimens. These findings were confirmed by FTIR and Raman spectroscopic analysis. Although further testing is needed to confirm the instrument's effectiveness, the method appears to offer a quick and simple way to identify impregnation-treated gems.<\/p>\n<p style=\"text-align: center;\"><strong>Conclusion<\/strong><\/p>\n<p style=\"text-align: center;\">Jade's value continues to rise, and this trend shows no sign of weakening, especially in Asia \u2014 China and Korea. New treatment techniques intended to improve its appearance and artificially increase its value are constantly advancing. The extreme rarity of jadeite jade, particularly imperial jade, encourages the proliferation of imitations and increasingly sophisticated treatments. Laboratory instruments such as infrared or Raman spectroscopy should be used systematically for stones resembling the finest qualities of jade. The recent discovery of DiamondView's effectiveness offers solid grounds for optimism in the development of methods for identifying treated jade.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33863 aligncenter\" src=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-13.jpg\" alt=\"\" width=\"350\" height=\"144\" title=\"\" srcset=\"https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-13.jpg 350w, https:\/\/ckystones.com\/wp-content\/uploads\/2024\/10\/telechargement-13-150x62.jpg 150w\" sizes=\"auto, (max-width: 350px) 100vw, 350px\" \/><\/p>\n<p style=\"text-align: center;\"><em>Type B+C treated jade (Eurojade) <\/em><\/p>\n<p style=\"text-align: left;\"><strong>BIBLIOGRAPHY<\/strong><\/p>\n<p style=\"text-align: left;\">Jade, Roger Kerverne, Lorenz Books, 1995<\/p>\n<p style=\"text-align: left;\">Jade, des empereurs \u00e0 l\u2019Art d\u00e9co, edited by Huei-Chung Tsao, MNAG, 2016<\/p>\n<p style=\"text-align: left;\">Chinese Jades, Ming Wilson, Victoria &amp; Albert Museum, Far Eastern Series, 2004<\/p>\n<p style=\"text-align: left;\">Wan Bresson, Les Traitements de la jad\u00e9ite, University Diploma in Gemmology dissertation, 2011<\/p>\n<p style=\"text-align: left;\">Testing Fei Cui Jade (Jadeite Jade), the Gemmological Association of Hong Kong (GAHK)<\/p>\n<p style=\"text-align: left;\">\u2018Jade\u2019 article on the GIA website (Research and News)<\/p>\n<p style=\"text-align: left;\">\u2018Color origin of lavender jadeite\u2019, Gems &amp; Gemology, Winter 2012, Vol. 48, No. 4, pp. 273\u2013283<\/p>\n<p style=\"text-align: left;\">Augustin Damour: \u2018Notice et analyse du jade vert. R\u00e9union de cette mati\u00e8re min\u00e9rale \u00e0 la famille des Wern\u00e9rites\u2019, Comptes rendus hebdomadaires de l\u2019Acad\u00e9mie des Sciences, Vol. 56, 1863, pp. 861\u2013865<\/p>\n<p style=\"text-align: left;\">\u2018Application of the DiamondView in separating impregnated Jadeite\u2019, Larry Tai-An Lai, Gems &amp; Gemology, Fall 2016, Vol. 52, No. 3.<\/p>\n<p style=\"text-align: left;\"><strong>Websites: <\/strong><\/p>\n<p style=\"text-align: left;\">Geminterest.com<\/p>\n<p style=\"text-align: left;\">Gemmo.eu<\/p>\n<p style=\"text-align: left;\">Gems-plus.com<\/p>\n<p style=\"text-align: left;\">Eurojade.com<\/p>\n<p style=\"text-align: left;\"><strong>Cover photographs<\/strong> : Openwork dish with a dragon motif, nephrite, Lia or Song dynasty, eleventh century, National Palace Museum, Taipei<\/p>\n<p style=\"text-align: left;\">Necklace of 27 imperial jadeite beads, dating from the late Qing dynasty (1644\u20131912), Cartier<\/p>\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>Fran\u00e7oise Li-de Vries\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<\/p>","protected":false},"author":5,"featured_media":34617,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"page_builder":"","footnotes":""},"categories":[139],"tags":[],"class_list":["post-15","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-memoire-gemmologique"],"_links":{"self":[{"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/posts\/15","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/comments?post=15"}],"version-history":[{"count":12,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/posts\/15\/revisions"}],"predecessor-version":[{"id":34554,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/posts\/15\/revisions\/34554"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/media\/34617"}],"wp:attachment":[{"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/media?parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/categories?post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ckystones.com\/en\/wp-json\/wp\/v2\/tags?post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}