JADE (jadeite)

( Fr- jade; Ger- Jadeit; Nor- jadeitt; Rus )

JADE (jadeite), Na (Al,Fe)Si2O6.

A. Jadeite nodule, top (height - 8.5 cm) from Guerrero Negro, Baja California Norte, Mexico. Cal Graeber Minerals. (© photo by Jeffrey A. Scovil)

B.  Jadeite (height - 6.9 cm).  Norman Steele collection.   (© photo by Jeffrey A. Scovil)

C &D. Jadeite. Three-color snuff bottle (height - 7 cm), dated circa  1780-1850.  (©  photo courtesy of S. Bernstein & Co. San Francisco, www.bernsteinjadeart.com )  The carving on this snuff bottle is described as follows:  "two sages cormorant fishing among lily pads during the springtime. The artist has used the natural coloration of the original jadeite boulder masterfully. The colors depicted are emerald green, white and gray-black. The relief work is well rendered with a high degree of polish which is the result of the application of chamois or deer skin repeatedly on to the surface."   (©  photo courtesy of S. Bernstein & Co. San Francisco, www.bernsteinjadeart.com)

E. Jadeite (width - 2.8 cm).  Norman Steele collection.   (© photo by Jeffrey A. Scovil)

DESCRIPTION: Pyroxene jade consists wholly or largely of microcrystalline, typically blocklike grains of jadeite. The size and arrangement of the grains appears to account for the unusual toughness of this jade and also its relatively common grainy or dimpled appearance, which is evident when fractured surfaces are viewed with a handlens or simple microscope.  Guatemalan jadeite, which is somewhat atypical, tends to be relatively coarse grained, commonly including grains large enough to be seen with the naked eye;  in addition, some of it includes chromium-bearing minerals such as macroscopically discernible chromite.  Some jadeitic jade -- e.g., that from the famous Myanmar (formerly Burma) localities -- contains noteworthy amounts of other minerals such as acmite, actinolite, albite, analcime, edenite, diopside, enstatite, kosmochlor, muscovite, natrolite, nepheline, prehnite, richterite, tremolite and wollastonite. Geologists, in particular, refer to these impure jades by special names -- e.g., those with noteworthy amounts of diopside and/or acmite, which are typically dark green or nearly black, are often termed chloromelanite. See THE JADES entry for colors and some of the other properties that pertain to both Nephrite and Jadeite jade. 
    H. 6½ - 7 (typically slightly harder than nephrite)   
    S.G. 3.28-3.40
    Light transmission -  s
ubtransparent to opaque
    Luster  - ranges from glassy to oily or porcelaneous
    Miscellany -  many jade boulders have reddish, yellowish, orangy or brownish rinds.

OTHER NAMES: Scores of names have been applied to jadeite jade. Jill Walker in the tome edited by Keverne (1992) lists "common trade names" (i.e., both adjectives and complete designations for jadeite jade) as follows:

Some jadeites are, however, best known, even in the marketplace, by binomial designations with, for example, a color or place of origin as the first name and jadeite the second -- e.g., the lavender jadeites.  This is so for the just mentioned jadeites even though members of the group exhibit a rather wide range of colors;  indeed, some people prefer to use their impression of the color -- e.g., lilac, (deep) purple, even mauve -- for the first term of the binomial name rather than just lavender.  For a recent report about the source of the colors for lavender jadeites from two localities in Myanmar (formerly Burma);  La Ensenada, Guatemala; and Kotakigawa, Japan, see Harlow and Shi (2011). In addition, some terms used rather widely in the marketplace use an adjective -- some of which are of unknown origin or application -- and merely jade, rather than jadeite, as the name (e.g., ice jade, which can be described roughly as a light green semi transparent jadeite) , 

See the many things listed under the USES subheading in THE JADES entry.  In addition, some jadeite has been faceted for use in, for example, rings.  And, some translucent, virtually colorless jadeite has been fashioned into cabochons that closely resemble moonstone.   Also noteworthy:  Today, much Guatemalan jade is fashioned into replicas of Olmec and Mayan carvings most of which are sold to tourists.   In addition, special attention is directed to the book by Ou Yang (2003);  in chapters six and nine, she lists and illustrates a few uses and outlines processes of production and systematically considers jadeite appraisal and grading factors (color, transparency, brightness, grainsize, cracking, volume, and cut).

OCCURRENCES: Diverse -- e.g., in sequences of chiefly sedimentary rocks that have undergone relatively low-grade metamorphism and as dikes (lenses?) in serpentinites -- with less than a consensus among geologists so far as conclusions relating to their geneses;   and as alluvial boulders derived from bedrock occurrences.  Ou Yang (2003) lists the following occurrence designations:  New Mine skinless stone ("unweathered ...  in primary  ...  deposits"), Mountain stone (in mass wasting environments), Surface Water stone (angular pieces in rivulets), River stone (rounded stones in river beds), and Terrace stone (stones of whatever origin now occurring in terrace deposits).  She also lists the following categories based on the common skins or crusts on these stones:   Sandy skin (of various colors), water ("feels smooth") skin, and enamel skin.

NOTEWORTHY LOCALITIES: Tawmaw plateau -- e.g., from Hpakan district, near the Uru River, about 65 miles from Mogaung, northern Myanmar (formerly Burma); and near Manzanal, Motagua Valley, Guatemala.  Shigley et al. (2000)  tabulate localities and pertinent references for localities from which jadeite was recovered during the 1990s. One recently discovered (rediscovered?!!) jadeite deposit seems especially noteworthy: Translucent blue and blue-green jadeite, which closely resembles that apparently used for millenia, by pre-Columbian Mesoamerican Olmecs, was so-to-speak unearthed in 1998. -- A major hurricane-promoted flooding of the Motagua River of Guatemala, and consequent landslides moved large "bus-size boulders of Olmec blue jade" to, for example, river beds, where they were washed clean;   in addition, the movements exposed jadeite veins here and there in the bedrock (Broad, 2002).   Shigley et al. (2010, p. 210) include several world-wide localities in their list "localities of the 2000s." 

REMARKS: As already noted, some jade in the marketplace has been dyed, chemically bleached, coated with paraffin, wax or some resin and/or impregnated by a polymer (Fritsch et al., 1992).  Other known treatments, used singly, together, or along with those just mentioned include vacuuming,  the application of acid (commonly acetic acid) or a bleach to remove extraneous stains or other coatings, and heating to improve colors. The impregnation has been used to so-to-speak make the matieral more stable.  On the other hand, and quite remarkably -- in fact, in my opinion, ridicuously -- some of the dyeing has involved differential application of the dyes purportedly to make the jade take  a "more natural appearance." -- Wow!   See also McClure, Kane and Sturman, 2010, p.234.

In general, jadeite jade, unlike some nephrite jade, does not become dull with the passage of time.

It seems a bit ironic that the designation China jade is sometimes used in an almost generic way  to refer to jadeite jade even though most jade pieces from China are nephrite jade.

It is reported that "Doubly Fortunate," an intense green jadeite necklace was sold at a Christie's auction for nine million, 300 thousand  (i.e., 9.3 million) dollars.  (Anon.,  2014).

A jadeite boulder, reported to be the largest ever found, is on display in front of the Myanmar Gems Enterprise headquarters at Yangon, Myanmar (Koivula, Kammerling and Fritsch, 1992, p. 132).  Apparently recovered from the Khy-Siu mine in the Mogaung area of Myanmar (formerly Burma) in July of 1982, the boulder has a circumference of 8.75 meters (~29 feet) and has been calculated to weigh about 33 metric tons (36 tons).

SIMULANTS, etc.: See those given in THE JADES introductory entry.   In addition, it seems noteworthy that some items fashioned from nephrite jade have been marketed as jadeite.

Also noteworthy here is the fact that some jadeite, especially that of certain colors (e.g., lavendar), has been dyed;  the dyes, frequently organic, may be used to give virtually all the color of  a given piece or merely , for example, make the piece have a more homogeneous overall color.   In any case, a recently reported investigation Lu (2012) indicates that the presences of manganese is responsible for the the color of natural lavendar jadeite, which is described as applied "to a broad range of colors from pinkish, purplish, violetish to bluish hues" (op.cit., p.275)  This fact provides a way to distinguish between naturally colored stones of these hues and dyed stones:    "Reddish (or blue/green) fluorescence reaction from deep UV radiation is a likely indication of the presence (or absence) of manganese ..." (op.cit. p.282)   One has to wonder, however, if this procedure, if used alone, might lead to the identification of some originally  purplish jadeite with its color enhanced or made to appear more homogeneous with dyes as "wholly" natural.
Jadeite-resin doublets etc. - Such assembled stones, along with acid-treated and both resin-filled and resin-impregnated jadeite are well described by Ou Yang (2003, Chapter eight).

***Synthetic jade -  "General Electric (GE) Gem Technology has developed a proprietary process for manufacturing synthetic jadeite . . . The samples [supplied the GIA Gem Trade Laboratory] ranged in color and quality ... but the finest green material rivaled 'Imperial' jade . . .  [this . synthesis is said to be] achieved in a high pressure environment . . . [and] The gemological properties of the small number of samples we have tested to date overlap those of natural jadeite." (Moses, in Moses et al., 2002).  See also  Renfro et al. (2011).

***Jadeite of less that top quality has been coated with an organic polymer that improves its color and overall appearance  has been reported by Zhang, Lu and Chen (2013).  This material can be distinguished from non-coated jadeite in several ways.  For example, "Coated jadeite feels dray and rough..., feels warm, unlike the smooth, cold surface of uncoated jadeite.., [has a] .the Mohs hardness [of ~] 3...,  and ( often display[s] ...traces of scratching (op. cit. p. 248). 

REFERENCE: Hargett, 1990;  Lu, 2012;  Ou Yang, 2003.  

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