Thursday, October 29, 2009

Jade - how to find this extraordinary gemstone.

Jade is the gemologist's term for two different mineral species: nephrite and jadeite. These two minerals are nearly impossible to distinguish from one another without the aid of mineralogical and XRD (x-ray diffraction) tests.

Nephrite is categorized as an amphibole and consists of extremely dense and compact fibrous tremolite-actinolite; and jadeite is categorized as a pyroxene, and also forms dense and
compact material.

This map from the Wyoming Geological Survey is unfortunately misleading. The only place in the state where neprhite
 Jade has been identified is in the central part of the state in the Granite Mountains and Crooks-Gap Green Mountain near 
Jeffrey City. All other localities are questionable. For example, the author was unable to find any jade in the Seminoe Mountains
during two years of field investigations (Hausel, 1993, 1994), and the occurrence along the southern edge of 
the Wind River Mountains (Prospect Mountains) was later examined and all the material reported as nephrite jade was
 amphibolite (Hausel, personal field notes).
Many rocks are mistaken for jade. Some of the more common include rounded, stream-worn or wind-polished cobbles of amphibolite (a dark metamorphic rock that resembles dense basalt), metadiabase (another dark metamorphic rock that also resembles basalt), epidotite (a dense pistachio green rock), quartzite (granular rock that can be white, dark gray, green or other colors) and serpentinite (dark green rock that can be scratched with a pocket knife). These rocks can be distinguished from jade by a couple of tests including simple field observations. For example, amphibolite and metadiabase have granular texture that is lacking in most jade (jade is smooth and massive without granular texture). A freshly broken surface of quartzite will sparkle in sunlight due to the reflection of light bouncing off individual quartz grains; and epidotite has a distinct pistachio green color (unlike jade). One of the more common rocks and minerals mistaken for jade is serpentinite (a rock formed mostly of serpentine). Jade is tough and hard, whereas serpentinite is relatively soft and can be scratched with a pocket knife. In addition, serpentinite will have pockets or zones of weak to moderate magnetism that can be detected by a geologist’s magnet. I’ve never seen a piece of magnetic jade, although some probably occurs.

I’ve seen serpentine sold to unsuspecting tourists as apple green jade. I even showed one rock shop owner from Riverton that all of the material he was selling as high-quality jade was serpentinite, but he refused to listen and continued to sell it as high-quality apple-green jade – and probably still does to this day.

When prospecting for jade, note that large jade boulders will ring when struck by a hammer. They feel much heavier than ordinary rocks, and are much smoother and denser than other boulders. Some boulders and cobbles of jade are so smooth that it gives an impression the stone was polished in a rock tumbler. Jade feels slightly sticky when wet and prospectors will look for a “show point,” area where the green color shows through altered rinds that encrust much detrital jade.


Light green muttonfat jade from the Granite Mountains. Note the crystal is
hexagonal (6-sided) just like quartz. This jade replaced a former
quartz crystal leaving behind this rare pseudomorph) (W. Dan Hausel,
collection)
Jade never shows external crystal structure except in rare cases where it pseudomorphs, or mimics the crystal habit of another mineral. I had heard about this phenomenon from a couple of rock hounds over the years, but never witnessed it until about 15 years ago when I found a pocket of hexagonal jade in the Granite Mountains (Wyoming) northeast of the Red Dwarf ruby deposit near the Tin Cup area that had the same crystal habit as quartz.

Microscopically, jade will form a mass of matted, intricately interwoven fibers that produce an extremely tough gemstone resistant to fracturing. Mineral toughness is rarely considered in mineralogy books, but any discussion of jade always leads to a discussion of toughness. The toughness of a mineral is represented by its fracture strength or ability to resist fracturing, which is about 30,000 psi for nephrite. In other words, it takes a lot of pressure to fracture a coherent piece of jade. Only carbonado, a black granular to compact industrial form of diamond, is tougher than jade; whereas gem-quality diamond is hard, but not all that tough. Gem diamond can scratch almost anything, but it can be smashed with a little effort with a blow from a hammer. It is the toughness of jade, combined with hardness that makes the gem carvable, durable and unique.
Look closely at this jade and you will see several individal jade crystals that are roughly hexagonal. These are also jade
 pseudomorphs after quartz. During the geological past, the jade slowly replaced the quartz one atom at a time without
 disturbing the original crystal habit of the quartz (W. Dan Hausel, collection).

Jade ranges from opaque to translucent masses and has a vitreous to waxy luster and is reported in a variety of colors including black, white, and several shades of green. The green color is due to the presence of iron. When iron is absent, the mineral is practically colorless to cloudy white, resulting in a variety known as ‘muttonfat jade’. Other varieties of jade include translucent, emerald-green ‘imperial jade’; ‘apple-green’ jade, ‘olive-green’ jade, ‘leaf-green‘ jade, ‘black‘ jade, and ‘snowflake’ (mottled) jade. The greater commercial values are attached to the lighter green translucent varieties. Rare emerald green jade is colored by iron and trace amounts of chromium.

The extraordinary color of apple
 green jade from Wyoming.
The origin of nephrite jade was investigated in the 1960s. It is thought that nephrite formed by metasomatic alteration of amphibole during metamorphism. This means that hot fluids reacted with existing amphiboles and slowly replaced them by extracting some atoms and replacing those atoms with new atoms. In Wyoming, this happened when these rocks were buried under several miles of rock about 2 to 3 billion years ago. Blocks of amphibolite were disrupted and trapped in a molten granitic rock and portions of the amphibolite (xenoliths) were altered to jade by the hot granitic fluids. These reactive fluids not only produced jade, but they also altered the surrounding rocks to produce a group of minerals that included clinozoisite, zoisite, sericite and chlorite.

When found in outcrop, nephrite jade is associated with this distinct assemblage of minerals that form an alteration halo around jade. This halo consists of bleached leucocratic (white) granite-gneiss that is mottled pink and white, some secondary greenish clinozoisite, pink zoisite, pistachio green epidote, green chlorite and fine white mica. This alteration halo can be used as a guide to find hidden jade deposits. While exploring between some jade deposits north of Jeffrey City to the jasper deposits in the Tin Cup district to the west, I found more than a dozen such halos – a couple had exposed jade, others did not. The ones without jade, such as shown in the photo below, likely have hidden jade at shallow depth.

Wallrock alteration found with jade includes bleached white granite
gneiss with pink zoisite, green chlorite and trace epidote. While
searching north of Jeffrey City, I found more than a dozen areas
with this characteristic alteration halo. Where found, this halo represents
places where jade or hidden jade is likely to be found (with some digging). 
The name jade comes from the time of the Spanish conquest of Central and South America where jade and jade carvings were prized as much as gold by the Aztecs. The Spanish used the name piedra de hijada, or stone of the side, because it was believed that jade cured kidney ailments when applied to the side of the body. The Spanish also called this stone kidney stone or piedros de los rinones, which translated into Latin as lapis nephriticus. The term nephrite anglicized the Latin term for jade. Nephrite has been known as ‘axe-stone’ because many nephrite stone artifacts have been found that were shaped into axe-heads due to its toughness. Although primary deposits of jade are important, much of the finest material comes from secondary alluvial deposits.

Some incredible pieces of jade have found their way to the jewelry industry. For example, one small jadeite ring sold for more than US$2.4 million: a 27-bead emerald green jadeite necklace sold in Hong Kong for US$9.3 million. In 1999, a 2-inch diameter (0.33-inch thick) jadeite bangle sold at a Christie's auction for US$2.6 million and a jadeite cabochon of 1.4-inches in length sold for US$1.74 million!

Black Jade from Wyoming
All of the jade found in Wyoming is nephrite, whereas much of the jade mined in the Orient is jadeite.

Translucent Jade cab 
from Wyoming

For those interested in searching for jade in Wyoming, it is found primarily in the Granite Mountains and to the south at Crooks Gap-Green Mountain. It has been reported elsewhere in the state, but much of the material reported outside of the Granite Mountains has turned out to be serpentinite.

The best jade specimens found in Wyoming are peb­bles and boulders in alluvial fans and soil around Jeffrey City. Cobbles and boulders are found south of US Highway 287 (789) while jade (in place) is found in outcrops to the north of the highway in the Granite Mountains.

Another strange rock. A former igneous rock (trachyte porphyry) from
the Granite Mountains, Wyoming, that was replaced by nephrite jade (W.
Dan Hausel collection).
The jade localities are described in the following books:

Hausel, W.D., and Sutherland, W.M., 2000, Gemstones & Other Unique Minerals & Rocks of Wyoming - A Field Guide for Collectors: Wyoming Geological Survey Bulletin 71, 268 p.

Geisha dressed in jade - 
colored pencil sketch.
Hausel, W.D., 2006, Minerals & Rocks of Wyoming, A Guide for Collectors, Prospectors and Rock Hounds, WSGS Bulletin 72, 125 p.

Hausel, W.D., and Sutherland, W.M., 2006, World Gemstones: Geology, Mineralogy, Gemology & Exploration: WSGS Mineral Report MR06-1, 363 p.

Hausel, W.D., 2009, Gems, Minerals and Rocks of Wyoming. A Guide for Rock Hounds, Prospectors & Collectors. Booksurge, 175 p.

A great majority of in situ jade is found north of Jeffrey City (T30N, R92-93W). Many were prospected in the past and thus most are now marked by old prospect pits. Look on Google Earth for prospect pits and then visit them.


Massive emerald green Wyoming jade
Jade was at one time highly sought after by Wyoming prospectors. But much of the high-quality easily found, emerald-green and translucent jade was found in Tertiary conglomerates at Crooks Gap. Lower quality light-green jade was found in place to the north of Crooks Gap in the Granite Mountains, but the source of the valuable emerald green was never identified and remains to be found. In the 1930s and 1940s, many jade boulders weighing several hundred pounds were found near Jeffry City in central Wyoming.

Jade carvings
Jadeite has never been found in Wyoming. It forms at high-pressure and low-temperature from near surface to depths as great as 30 miles. Geologically, it is found near convergent continental margins (where there is considerable pressures and temperatures from tectonic stress), and forms by fluid interaction with serpentinizing peridotite at depth. It occurs in veins and masses within metamorphic rocks, particularly albitite, actinolite schist and/or serpentinite. Most jadeite is found in highly faulted, subduction-related serpentinite or m̩lange along major fault zones Рsuch as in California.

Extraordinary specimen of polished
 jade from Wyoming with rind
Only three countries produce jadeite on a commercial scale: Burma, Guatemala and Russia. The jadeite from Guatemala is granular, mottled, and opaque. Burmese jadeite has more intensely saturated colors of deep-lavender to emerald- imperial green. Jadeite from Russia, although generally dark-colored, tends to sit between the Burmese and Guatemalan jadeite. Jadeite has not been identified in Wyoming.

Nephrite jade is produced primarily by Canada. Wyoming produced large quantities of fine nephrite in the past, but there is no longer commercial production. Russian nephrite was exported to China in the past and most Russian jadeite was sold through markets in Hong Kong as Burmese jadeite. In Eastern Turkistan, the jade market is strictly controlled by the Chinese government and only government buyers can purchase jade at the price set by the government.















Can you guess which of the two minerals above is jade? The specimen to the right (above) is weakly magnetic, with little zones of magnetism best  detected with  a pencil magnet (see http://www.minerox.com/). And with a little effort, it can also be scratched with a pocketknife, unlike the real jade (nephrite) to the left.

Intrigued by all of the treasures out there in the world to be found? There are geological hints on where and how to find jade and hundreds of other mineral deposits. Many of these are described in my books  at Amazon.

ABOUT THE AUTHOR -
W. Dan Hausel, a.k.a the GemHunter, was privileged to work as a research geologist for the Wyoming Geological Survey at the University of Wyoming for three decades. During those years, he periodically took leave of absence to consult on gold, diamond, and gemstones in the search for additional deposits outside of Wyoming. Over the years, he published more than a thousand books, maps, professional papers and abstracts, and mapped more than 1,000 square kilometers of complex geological terrain, while finding hundreds of mineral anomalies including one of the largest gold deposits ever found on earth (with 6 colleagues).




Wow, can you believe this specimen? Jaded brains. That's right, the last State Geologist I worked for at the Wyoming Geological Survey had his brains removed and we examined them under a microscope and found them to be replaced by jade (just kidding - about the replacement - there were no brains to be found).

My good friend, Dr. J. Dave Love (RIP) sits on large Wyoming jade boulders in a garage in Wyoming.












36 comments:

  1. Thanks to your teachings I have a 40 pound piece of jade found in Nederland Colorado. It looks just like the cabochon you have a picture of, transparent with green blotches.

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    1. Funny, I have good reason to believe that I have found a
      jade pseudomorph and a few considerably large chunks of Jadeite (with rind) in nederland-nederland(i.e the netherlands

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  2. I found translucent green jade in Wyoming

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  3. A beautiful piece if you're interested in seeing it you can contact me at ronniefranklin53@yahoo.com

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  4. this is is a great blog! I learnt lots of things for my blog on war history and geology! be sure to check out my blog at http://oansell.blogspot.co.uk/

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  5. Very informatative and interesting. Thanks to author. I am from pakistan. I think i should plan for a jade hunt.

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  6. I just read on Amazon, that California jade is banned from being sold on their website because it's Californite and not jade. Is this true? I thought there was jade to be found in California...

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  7. We found what I believe to be ventifact black jade between Lander and South Pass, Wyoming.

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  8. I have tons of Jade available from Pakistan and am looking for buyers. Sample can be seen in Toronto area and mine visit can be arranged.
    I also have Chromite, Manganese, Iron and Copper ore.
    Also have black marble.
    Please contact me for further details

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  9. The gold bearing jadeite of California,written of in the California Division of Mines and Geology,Special Publication 49,takes a beautiful polish.If you internet search/gold bearing jadeite/ and view the uncut gray viewed there,enjoy the gold plated onto the quarter extracted from previous cabachon production of gold bearing jadeite.Have you worked with this gold bearing jadeite,and if so,are you able to cut the gemstone with the ability to ensure the precious metal inclusion to be center placed?We are now working with several mineral and gem societies of Ohio to research the same type of gold bearing jadeite.Thanks Ray. P.S. The Smithsonian led this research in the early 1970's shortly after the "Smithsonian Agreement of 1971"

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  10. We are waiting on a current assay of gold bearing rock.Jadeite,granite,and shale.All related to gold and research led by the Smithsonian since 1971.Nearly twenty mineral and gem societies have helped to gather the related rock.The gold bearing jadeite was the main focus of this nearly 50 year effort,and the results are only now being enjoyed.I am only the rock guy,just blessed with having been led by men like Mr. Edward S. Rader,board of director for the Smithsonian,with related duties for the National Science Foundation.Mr. Edward S. Rader was born in Irvine Kentucky over 100 years ago and his earth science knowledge influenced today's factual truths of glacial deposits,and creation.

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  11. I think I have a Jade I got from a kids toy, It's not quite the same as your quartz-jade its just the opposite I think it is mostly yellow jade with specks of pyrite or crystal quartz? check my google+ for the picture

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  12. I think I have a large chunk of olive green Jade found in Arizons

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  13. The only opinion of jade that matters is that of the person buying it.....

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  14. I have a rough piece of Jadeite found on the north shore of lake superior. Lake Superior Agate country

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  15. Good job thank you for the information I will use it with the blessing from GOD and find some. Thanks again

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  16. Thank you for the education. Can I submit a picture to be identified on here?

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  17. Nice blog ! Thanks for sharing best information with us... We are the best dealers for Green Jade and other gemstones in delhi, do visit gemtre .

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  18. I quite a large amount of fine grained under tremendous pressure green stone from an extensive surpentinite field and I believe that there is a lot of blocky monoclinic nephrite { green } and also a lot of monoclinic with a twist Serpentinite but super hardened, I mean as hard if not harder than the nephrite and also an even greater amount of nephrite and serpentinite blended which looks awesome. The 2 Side by side places this came from was a volcanoe on a major fault line which never erupted for over a million years , storing everything down below until a major 8,5 tectonic shift slammed into to it to
    come up only to slam into the massive bedrock and sprayed off that at forty five degee angle and south covering miles with 1,000 feet of sepeninite and nephrite. Some pretty interesting stuff came out of thereThe other place 5 miles to therast was not a volcano meary a hot spot that stayed hot for over a million years then died out and if it wasnot for the ice age carving its way through it would have stayed buried.Even better here.There is no one here that knows jade around here so i will have take some samples to a university geology department to be examined but I am wondering if its all for nothing as China looks like they are not going to be buying nephrite for a while but I do not know of any one else buying plus I never find translucent only opaque, very dense though

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  19. How does anyone know where to actually look for jade - virtually everything I've read when asking how to know where to look is so vague as too be of no help at all

    Typical answer to where to locate jade is: "Jadeite and nephrite are mostly found in metamorphic rocks associated with subduction zones. So most jadeite and nephrite deposits are found along the margins of current or geologically ancient convergent plate boundaries involving oceanic lithosphere." Phew! Something tells me that even if one could actually locate margins of current or geologically ancient convergent plate boundaries it wouldn't really narrow down the search. Based on that you could probably look for years and not even come close to locating an area that may have jade....or be in the right area and fail because you have no idea what to look for...

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  20. An excellent website! Very informative & helpful. I have several Jadeite specimens, as in breccia within breccia inclusions of plagioclase, Ni, Cr, Ti, and Fe. Most of these stones attract a rare-earth magnet in short order, and would appear to be Cloromelanite. All specimens ring with tap of a pick hammer. All of these stones show signs of ablation, as in directional flow lines and thumbprints. As we are discovering from Lunar & Martian mapping, both bodies have large basins of Olivine, which is directly related to Jadeite and other rare gems. Perhaps you might have an opinion on these descriptions? Thank you in advance

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  21. An excellent website! Very informative & helpful. I have several Jadeite specimens, as in breccia within breccia inclusions of plagioclase, Ni, Cr, Ti, and Fe. Most of these stones attract a rare-earth magnet in short order, and would appear to be Cloromelanite. All specimens ring with tap of a pick hammer. All of these stones show signs of ablation, as in directional flow lines and thumbprints. As we are discovering from Lunar & Martian mapping, both bodies have large basins of Olivine, which is directly related to Jadeite and other rare gems. Perhaps you might have an opinion on these descriptions? Thank you in advance

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  22. Wow. I had his son Charlie for Geology at Western. Thanks for the picture!

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  23. I have a jadeite dragon pendent
    I think it's the real deal.
    Anybody know?

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  24. I have a 40 lb rock what appears to be jade. A lady working in a gem shop said it was serpentine an worth little. I dont know

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  29. You have done a great blogspot here. I have a very rare piece of Nephrite jade which I have just recently built a website for. This piece is a slab, one of 5 exploratory slabs taken from the Polar Pride in 2000. To view go to stoneofheavennephrite.com . I have had it since 2000 and felt it should be viewed, mainly because there's no more available. The Polar Pride was deemed to be "the hardest, most brilliant most transparent GemStone quality Nephrite found". Take a look and please leave your comment. Two of the sister cuts are in the Smithsonian Gem Gallery.

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