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Identity HelpIdentifying White Jade

10th Jul 2013 16:48 UTCAlan Weigand

Howdy folks!

Bought this piece of what I suspect is white jade carved into a floral amulet. I would like to sell this but not really sure the best way to explain what type of jade this is. The more I read about it the more confused I become.

The item is cold to touch. It measures 1 and 3/4 inches by 1 and 1/4 inches and is about 1/4 inch thick. I tried a scratch test with a sharp piece of carbide steel as well as a sharp piece of quartz and had very little luck making any type of small scratch mark.

The light used on the back illumination is just a typical old flashlight bulb non LED. 19.7 grams is weight of the piece and feels heavy for its size.

I am not sure of its age with 100% certainty but a consensus on what kind of jade this is would be helpful. I dont think this would fall under jadeite because of the color so that leaves nephrite, but what type?

Thanks for any help,

Al

10th Jul 2013 17:25 UTCTim Jokela Jr

Hopefully our resident jade specialist from Oregon will notice and reply.

She had a long list of how to properly and scientifically identify true jade.

One of her failproof tests involved wrapping a hair around the rock in question and lighting it.

The hair! Not the rock, silly.

If the hair failed to ignite, proof positive it's jade.

Thermal conductivity, you see.

YMMV.

I would direct you to her thread, but it was sadly deleted by the forum's heavy-handed British overlord, which was a shame, as it was one of the funniest things ever. I am highly tempted to resurrect it via the Wayback Machine, print it out, frame it, and hang it on my wall.

10th Jul 2013 17:52 UTCAlfredo Petrov Manager

A few years ago I wrote on a few other tests you might find useful: http://www.mindat.org/article.php/883/Jade ...nothing about the burning hair test, I promise :-)

Gemmologists will recommend you send it to them for more professional tests, but I think amateurs should do as many tests as possible themselves first - it's a very educational experience - and then send it on to professionals if the kitchen test results are inconclusive.

11th Jul 2013 01:17 UTCOwen Lewis

Hi Al,

I think you have three questions, each to some extent depending on the answer to the one before:

Q1 - If this object jade? Y/N.

Q2 - If yes, then what type of jade is it?

Q5 - What's it worth?

There are two missing questions before you can hope for an indication to your last one. These are:

Q3 - If a jade, has it been treated? Y/N.

Q4 - If Y then what have been the treatments?

That's the game plan. Then the bad news.

- Yous pics are too low quality and of the wrong sort to allow much comment, except:

- The carving appears to be of a crude 'tourist art' quality, indicating that, if jade, it is not of much value (those who buy jade in the rough are very expert is assessing their purchases and don't waste valuable jade with crude workmanship.

- That it is white does not prevent it from being jadeite - but the most valuable jadeite is never white.

Sooo... The longest journey starts with a single step. What step? Examine it carefully with a backlight to confirm that there are no major inclusions or flaws (from your pics, I'd say you are in with a good chance of that). If OK then weigh the piece in air and water and calculate the SG to 2 decimal places. To do this and for a piece of the size you have, you will need a balance accurate to at *least* 1/10 g and accuracy to 1/100 g will be better.

Next, you need an indication of the refractive indices of the material. Without alteration to the piece, this can't be done properly but even a vague indication (which your piece should yield up) will be a help in identification. This will require a totally internally reflecting refractometer and some reasonable experience in getting some usable result from 'difficult' stones.

And next a careful and all-over examination of the finish and structure of the stone in both transmitted and reflected light. Using a x10 loupe and a hand-held white light source will probably do - if you already know what you are looking for - but a decent microscope with various illumination options and x10 - x40 magnification options will do much better.

Unless you are already tooled and trained up to do these tests and a couple of other fiddles, then you need to give the piece to a friend who is and will do them for you. You may have a local Rock and Gem club, a member of which might be happy to help you out. Failing all else, if you PM me, I'll do it for you at only the cost of the return postage. Written report to you only by e-mail, for you to publish here or share with others as you choose.

You can expect this to give you a Y/N to Q.1. and if Y then an answer to Q.2. You might also get a first indication of answers to Q 3 and 4. You will not get - from me at least - an appraisal of value. Appraising Jade is notoriously difficult and a specialism requiring about five years of working under supervision on several valuable pieces daily for around five years before you are fit to be let loose. Off hand and just off your pics, I'd say that there is no reason to think your piece could be worth much more than 100 bucks and probably less.

PM if you want to proceed.

Best,

Owen

16th Jan 2016 20:01 UTCmichelle abernathy

Hello Owen,

would you be willing to test a "white jade" necklace I bought on Etsy? Upon receiving the necklace it sure seemed to me more like glass or milkglass. I asked the seller about it and she noted thather mother "wore this white jade necklace often" which of course is anectodal not conclusive evidence. I don't have a bone to pick, just curious if it is or isn't. :)

Attached is a basic picture. For one, I would think there would be knotting between the beads

Thank you,

michelle

16th Jan 2016 21:17 UTCOwen Melfyn Lewis

Hi Michelle,

I think I need to decline.

Determining the specific gravity is an essential test which can't be carried out on your piece without removing a single bead and then re-threading the string afterwards. There is nothing difficult in this but it is work that I do not do and would have to outsource the re-threading after testing. Cut one bead loose and the whole string has to be broken up and re-strung.

You say that the strand is knotted between the beads. This does not show in your pic. But, if it is so knotted and the threading material is silk strands, then someone thought sufficient of the beads to do the job properly and the beads are not likely to be glass (which would be threaded on cotton or nylon etc.)

Any assay/maker's mark on the clasp?

A 'home-test' you can try is as follows. Beg, borrow or steal a glass marble from some small child. Keep it next to your necklace for a day at room temperature. Then touch the marble to your lips (no lipstick!) and immediately afterwards do the same with one of your beads. If the sensation of coldness is about the same for the marble and the bead, then you probably have glass beads. However, if your bead feels markedly colder that the marble, then it is *not* glass (or any resin or other plastic) but is some crystal. The crystal is not necessarily jade but, if you have quality stringing as well, the chances of it being jade are reasonably good.

Sadly, whether or not it is jade not the end of concerns. Jade may be untreated (type A), dyed (type C), resin-filled (type B) or dyed and filled (type B+C). Either or both of these treatments reduces the value of a piece substantially.

Here's a link you may find helpful. http://nelsonbeads.com/collections/white-jadeite . Those I have tested ;-) Price is per string and not per bead. A string of untreated good quality jadeite beads can fetch a thousand bucks, easy, at auction.

16th Jan 2016 22:39 UTCDoug Daniels

I believe she said there is no knotting between the beads, so maybe, .......

17th Jan 2016 01:17 UTCOwen Melfyn Lewis

Tsk.... Thanks Doug....

Michelle,

Try the 'lip' test. It's a very simple test but actually based on good science; the lips and tongue are very sensitive to even small changes in temperature and crystals are a better conductor of heat that is glass. If you can't feel that one of your beads is 'colder' on your lips, then the bead is almost certainly not a crystal and you should have no need to enquire further. N.B. Glass jewellery has been around since the days of the Romans :-)

OTOH, if you do find a temperature difference and as the necklace is 'economy strung', if you want to snip the string and send me just a couple of the beads, I'll test them for you and let you know what they are and you can restring the necklace when you get them back. PM me if and when you want to go ahead with this

and we can swap the necessary details by e-mail

20th Jan 2016 07:32 UTCAbdulB Sh

A real jade is smooth without any visible bumps, and one more test,

When jade loosely collides against other jade, it makes a clear, almost musical tone.

20th Jan 2016 13:38 UTCOwen Melfyn Lewis

AbdulB Sh Wrote:

-------------------------------------------------------

> A real jade is smooth without any visible bumps,

> and one more test,

*Definitely* false. An 'orange-peel' finish is very commonly - but not always - present on polished jade. So much so that it is taken as one indicator that a piece showing it *is* likely to be jade.

> When jade loosely collides against other jade, it

> makes a clear, almost musical tone.

True, but:

- Jade is only sometimes a single mineral (e.g. nephrite or some jadeite). Commonly, it is a solid solution mix of minerals (much jadeite, omphacite and kosmoclor). It follows that to 'ring' with a pure tone when gently struck with something hard, cannot be a unique property of 'jade'. As is well known, it is also true of many hard solids, be they crystalline (e.g. metals) or amorphous (e.g. a glass). It follows that this is no test at all as to whether an item is or is not jade.

- Jade (and other hard materials) that contains small cracks will not 'ring true'. The proper use of the 'ringing' test is to test quickly for the presence of any crack in the item (particularly bangles). A version of this test is widely used in engineering and some other field for checking hard metal objects for hidden flaws.

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