Chloromelanite

I need a little help understanding this mineral(?)...actually, just about everything. I have done the Google thing already...I'm hoping to get some deeper insights into what it is exactly. Probably most importantly, is it jadeite at all?

~Zeke,
JadeJunkee
Washington State

It is either aegerine-augite or omphacite (intermediate minerals between sodium (jadeite or aegerine) and calcium pyroxenes). - from the 1988 article "Nomenclature of pyroxenes " [www.minsocam.org]

To my knowledge it is the material marketed as Maw sit sit. The main source is the jadeite quarry in Burma according to a fellow I talked to in Tucson. Great looking stuff and costly for lapidary material. Mike

Thanks...slowly working this out in my head. Thanks for that link...I'll be interpreting that for awhile. From what I've read else where, I came to the conclusion that Chloromelanite was basically aegerine-augite. Maw-sit-sit seems to have a something that I haven't seen noted for all Chloromelanites though...that being the chromojadeite (that's the same thing as kosmochlor right?). Point being I was surprised Chloromelanite was a synonym for Maw-sit-sit...but it makes sense as a variety of Chloromelanite i guess. but i don't see it ALWAYS noted as haveing aegerine-augite??? I see albite though.

The stuff I am thinking of isn't as flashy as Maw-sit-sit, probably because it lacks that chromium. It is noted as being mostly aegerine-augite. it looks like a dark green to black nephrite as seen in artifacts from the Northwest (Washington, BC Canada, Alaska)

Anyway, here's the follow up question. From what I have read, all the 'Chloromelanites', like the omphacites, are noted as containing proper jadeite, just not normally the component with the highest percent. Doesn't this percent thing imply these stones are rocks not minerals then? Sort of like how nephrite is seen as a rock. Omphacites are described as a combination of minerals...including both omphacite (a mineral) and jadeite. Is this a nomenclature problem? I see that Maw-sit-sit is a rock, so I assume chloromelanite is as well...but what about omphacite? seems like it is both a rock and a mineral.

I've also read that all these minerals (solid solution series) belong to the "jadeite group"...so how are they not considered jadeite then?

I'll leave it at that for now. thanks for your opinions. I hope I'm making some kind of sense

~Zeke,
JadeJunkee
Washington State

The problem with these names is that different people have used them in different ways that changed over time, sometimes just because analytical techniques got better. "Chloromelanite" has been used for green-black jadeite, aegirine-augite, omphacite... all of whose definitions themselves have at times been a bit fuzzy. And not all "black jadeite" is "chloromelanite" - some is the true species jadeite, colored black by microinclusions of graphite. For the sake of clarity, just strike "chloromelanite" from your vocabulary altogether ;))

The name "jadeite" itself is subject to some fuzziness, depending on whether the person using the term is talking about rocks, mineral species, or lapidary materials. As Mindat is a mineral website, we use the species definition: Na-Al-dominant pyroxene. The exact percentage of the Na-Al-pyroxene molecule is not important in the naming, it just has to dominate over the other molecules commonly present (omphacite, aegirine, kosmochlor, etc.) in the structure.

"Maw sit sit" is a rock name, not a single mineral. It is a mixture of several minerals, including jadeite sensu stricto.

thanks Alfredo...so I was basically on a wild goose chase. here's a follow up question that should be easy to answer then. who are "they" that decides what is and isn't jadeite jade and what is thier criteria? (I don't mean mineralologists...talking gem community here) I realize this is a fluid issue...just want to know the current state of affairs.

what is your take on the term jadeitite?

In my opinion, all jades are rocks. As long as they are in the proper mineral series and LOOK like a jade gem stone they are jade....just have to qualify it. I suppose a certain toughness and density should be expected...yeah...not very scientific

~Zeke,
JadeJunkee
Washington State

I am curious about Cloromelanite as well. I've read that it might as well be called Jadeite. It certainly has the right density and hardness, at least the stuff I have found in northern california, and is perhaps more dense. The beach specimens fell almost meteor-like. Can anyone recommend a place to send samples to be tested? If the majority of the rock consists of the Jadeite Na Al-pyroxene group, I can then happily call it Jadeite- what awesome stuff!

hi .i own a maw sit sit specimen ,a chloromelanite specimen and a african jade specimen (probably a green grossularite).i want to know if someon know the exact contains of each of this stone and if they can be classifieds as nephrite jade, jadeite or it's something completly different?it is their official name or a trademark name?i own many specimens of canadians jadeite or nephrite and they look very different from this rock.bye and sorry for my bad english.

maw sit sit is primarily the mineral kosmochlor

chloromelanite = very dark jadeite

african jade = grossular garnet

What he said ...the Canadian material is nephrite not jadeite...that's why it seems so different...but a picture would help confirm... Canada has other jade like materials as well, including the massive grossular....but it is most likely nephrite.

Jolyon,

According to analytical results performed by Pavel Kartashov and available in [www.mindat.org] , [www.mindat.org] and [www.mindat.org] , "Maw Sit Sit" is a rock consisting mainly (in one case, about ~98 vol.%) of chromian Jadeite (with 5-6 vol.% Cr2O3 and composition ~Jad85Ksm13Aeg2), some chemically pure Albite impregnated with minute μm-sized particles of Kosmochlor that give it a very deep emerald-green color and minor Cr-bearing sodic amphibole (chromian Magnesio-Arfvedsonite).

In a simplified way, it could be termed as an impure chromian Jadeite, or - more correctly - a Cr-bearing jadeitite rock.

Also, some very interesting information on the compositions of Kosmochlor and the Cr-bearing sodic ampibole from the locality, can be found here [www.mindat.org]

Lefteris.



Edited 1 time(s). Last edit at 06/10/2011 07:42AM by Lefteris Rantos.

hi exactly what im looking for about maw sit sit but l have a other if the person who's posted this topics allow me to do it. i own many different specimen of supposed jade like:purple jade turkey ,translucent jade mongolia(look like rough tanzanite with iron stains)a blue russia than i buy under the trademark name dianite .black jade with quartz veins from arizona.black jade with magnetite from a unknow usa locality maybe oregon i think .and some white jade with orange or yellow spot from china .the only thing im sure it's than none of this specimens had been dyed in any possible ways .what are the link between all this minerals than they can be call jade.i want to know of minerals thet must contains to be put for sure in the jade family?maybe they are only minerals use to carving objects and it's why peoples sell them under the trademark name of jade and if it's that i want to know if someone know what really are this natural specimen than i buy?bye and thank for the infos about my maw sit sit specimen .

Here are several pictures of what I'm trying to confirm is Chloromelanite/jadeite. I haven't found any pictures of rocks like these online. Also wondering where I can send samples to be tested. Thanks -Joaquin

Here is another photo of Chloromelanite/Jadeite for verification?

to me they look they could be either Chloromelanite or "just" nephrite....one or the other for sure for most of those. you'll need to do an SG test.

Hello Joaquin,

Please tell us if you tumbled or you bought the two "jade rage 014_1" tumbled stones?
Also please tell us if all of the "jem and mineral jade, rocks and matsutake 020" shown in the photo are from the same place.

The two "jade rage 014_1" tumbled stones are Andes Jade (http://www.mindat.org/min-31328.html).

The "jem and mineral jade, rocks and matsutake 020" photos shows several well polished Andes Jade. The unpolished ones are not Andes Jade.

Yanick,
a "dianite" is trade name for blue nephrite from the single locality. It consist of different amphiboles and microcline, so it is real nephrite.
[www.mindat.org] and [www.mindat.org]
[www.mindat.org] and daughter photos

Sorry to jump in here. However, have been searching for a long time for someone to discuss this with.

My wife and I have a large rock, about 2x football size. It's so heavy, it has to be slid onto my hand truck to move it. It is a rather dullish, white color, with pale greenish circular areas showing through the white, as though the inside is the pale greenish color. The rock is oval in shape, and smooth than rough.* It is quite beautiful to us. I took it to Western Washington University, Geology Dept., for identification. The professor came out to my truck to look at it, and pronounced it to be mutton fat jade, probably coming from a Canadian glacier. He showed me the University's collection of mutton fat jade, and they were miniscule in comparison. He tried for a long time to get our big rock. He said he wanted it for himself. *About the color: the pale greenish circular areas are slightly indented in the white outer layer.

I realize I need to take a picture/measurements and attach; however don't have them now. We're just too excited to ask our questions! How do I go about identifying our rock? We're in Bellingham, WA, which I don't think has any other resources than Western Washington University. However, I don't find any references anywhere to mutton fat jade, as the prof called it.

Any help or information will always be greatly appreciated!

I'm in Bellingham too...but go to the facebook page Washington State Jade Rendezvous: [www.facebook.com]


and jump on there..there is a testing program out of the same department you can link into as well as many of the local experts.

~Zeke