Deciphering Rodingites, paragenesis

Good comments from Franz. I' ve likewise seen the blackwall alteration zone at the margin of a commercial talc deposit at the Broughton Mine in the Quebec ophiolite belt (town of St-Pierre-de-Broughton). It's a green chlorite (actually clinochlore) schist.

[www.mindat.org]

If you look closely at this kind of rock, you should see the sparkly mica cleavage in the chlorite flakes and an overall schistose texture imparted by this mineral.

Small black grains seen in one of your photos of light-green serpentine(?) might be chromite or magnetite.

Woody Thompson



Edited 2 time(s). Last edit at 01/14/2010 02:20PM by Woodrow Thompson.

The light-green with small black grains is too hard for a serpentine. I believe it is most likely a bit of nephrite as I haven't seen any of the "near Jades" (hydrogrossular and vesuvianite) with those kind of inclusions...but for jade it is common. There's not enough of the material to do anything with though, so i threw it my rodingite box. I believe magnetite is what it is commonly siad to be...but chromite wouldn't be unheard of either.

No sparkly mica like cleavage to my eyes...I believe I understand what you mean by schistose texture...I don't see that either...but because i've read that not all schist looks schisty...what do I know then?

Now that said...there are others that may be just as you describe...I'll keep going through my collection. I have to reshoot each one though as I don't have good close ups on them right now.
I'm not sure I kept enough green-chlorite-schist-like pieces to put that piece of the puzzle together...I avoid green rocks that aren't jade to save my back getting out of the creek ...but I'm keeping an eye out as I go through the collection.

Sorry, I got off track with all that fake archaic jade mess. Here is is a piece that might help with the soft black stuff. It is from the well known Deer Creek locality here in Washington, Oso. It is mostly comprised of the soft black stuff with curious inclusions. might be the same thing as the Grandy creek soft black material, more or less. It's a good specimen because the "peak" on this piece is what is called hydrogrossular garnet by the jade collectors. Does this direct association give anyone a clue to the black stuff's identity? I call this rock "Cascades" because it looks like a snow cap peak and was found in the Cascades.

CASCADES SLIDESHOW

I'll only post this one picture, close-ups on the link above.

Interest in my rocks seems to have died That's Ok, it's a tough subject. for fun, here are two examples of the beauty of the grossular rodingites:
Slideshow of ameture backlit...later non-backlit.
Hello Rock

anothor pretty example of massive rock

Rodingite

~Zeke,
JadeJunkee
Washington State

Hi Ezekiel

Interesting posts, comparing with my slice of green, dark grey and white mineral. The black on my specimen isn't soft though .

Amanda

Interest has not died, but it is difficult to say anything definitiv. The soft, black stuff of your last photo could be a serpentine rock or a chlorite rock. But you know this already :)
Franz Bernhard

Yeah...I just wanted an excuse to show my pretties
Amanda, thegrey on yours might be grossular...it can be white or grey translucent or opaque.

......................but it should be quite hard and heavy........

Moving on....Found this piece the other day...found a better one but left it for some reason....appears to be a hydrogrossular or vesuvianite in something i think someone called inesite. I guess this would be a zone in a high grossular garnet content reaction zones....purpleish....harder than a serpentinite style matrix but some "shinies" that hint at mica or tremolite or actinolite. Any thought welcome...if no, then you must think I'm right

"jade" in inesite?
~Zeke

Could someone move this to the scrapbook category? I would like to start posting to it agian soon without folks thinking I am requesting help with IDing....I am at a point that my guess is as good as anyones though I now call the soft blacks "serp/hornblende/chlorite"...mostly because I don't like being wrong and it isn't really that important as I am collecting the vesuvianites, nephrites and hydrogrossular garnets in the rodingites. though if anyone has an easy field test to distinquish the three I am all ears....

~Zeke,
JadeJunkee
Washington State

Because I got some help from the folks who replied to this thread, I thought would post a little about the jade finds I made in part thanks to that help. (technically jade is a rodingite, so this counts Unfortuantly, I can't disclose the exact location of these finds as it is generally held to be a "Show don't tell" site...that is you have to find it yourself to earn the right to know where it is....so I have to respect that, even though I found it myself. The creek is too small to handle every "treasure hunter" & rockhounding club (not to mention the folks selling the jade on the black market). there are also plenty of publically known sites that can handle everyone.

Here is the first post on the discovery..several more to come...


Big Toad Creek (Skagit County)

I went out today with my son to do a little prospecting on a nearby river. I was looking to find an alternate route to a jade bearing area mostly on the other side of the suspect and known mountains. The area I wanted to reach is closed off to vehicle traffic....and a ## mile hike isn't the best situation when carrying large heavy rocks. This wasn't the river I wanted to be on...but I was hopeing some jade was here too. I drove up to the end of the FS road and found a place to cut into the river....but the rocks on the creek betrayed the wrong geology...mostly all volcanics and basics....not ultra basics...just basics. Nothing hinting at jade.................... So I drove back down, paying attention to the peaks I was useing for reference to the USGS GG maps. I looked for a flat area where I could easily reach the river without having to deal with steep bluffs and cliffs. totally random. the peaks and generalized units I was shooting for were on the opposite side of the river from me (or so I thought...I was relying on memory and hadn't double checked before I left). I had no interest in the geology on the side I was on...as I didn't recall it being correct for jade...but those maps are hard to read and compare with road maps. As we walked toward the river we ran accross a little creek and decided to follow it down to the river. This is a no name creek....we call it Big Toad because of how many toads were on it. I could just as easily call it Dumb luck creek You don't even notice the creek as you drive up the road...very small and hidden.....as soon as we got on the creek, what do I see but our good friend rodingite...all over it. Blackwalls and tans. traveling down the creek I immediatly started finding the soapstone bots...including some with some nice color. the prize however was at the near bottom of the creek...the best stuff ever that is prettier than the best hydrogrossular garnet but has similiar colors. that's what I got...and a couple of smallish pieces on the way back up. The rodingite is not weathered down...so the source is very close... One last note: On the way up we had our windows rolled down...very near this spot....we heard a terrible noise...never heard such before....I'd say it was a primate This is the area some old timers (jade hunters) claim that the bigfoots guard the jade. I nearly ran off the road when I heard it...we must have startled it. Anyway, here it is...enjoy:


FULL SLIDESHOW:

[s790.photobucket.com]


DRY:


FOR SCALE:


WET:








Smily Face:






slicks like this are rare....I'm just learning to id the hidden ones. Went out agian today with My partner...only found one slick between the two of us...combined hunting time of 13 hours....but found some non-slicked ones too. very hard creek to hunt on. Steep...gravels don't get turned over....rocks covered in moss...not many small gravels to choose from....slippery...have to scramble a lot....bigfeet taunt you from the trees, throwing feces at you...gnats...oh god the gnats!.......................the lighting on the creek is so terrible, this looked like junk on the creek...so now we realize (as well as after studying the rinds of the other pieces we came back with) that we were walking right past this stuff....as well as passing this stuff by on most of the other creeks (the slicks having been mostly already picked up, so no chance to learn about the rinded material). I do have a few pieces from every creek I hunt on...but they always managed to convience me they were an HGG...just not so...this is jade, not the HGG i've been showing you in the past. One big dif is the heft...hefty enough to be jade, but not hefty enough to be HGG. Also, the hgg doesn't have the black chromite (?) specks...jade does, but not HGG....and these slicks feel soft whereas hgg just feels like a hard ass rock Notice how the jade gets opaqueish near the rind edge (and the color is not the brightest) 99.99% of this rock is translucent. it is also the same stuff as the Winter's jade in Oregon (tested as nephrite)
FULL SLIDESHOW:
[s790.photobucket.com]

DRY:





RIND TELLS:




WET:













BACKLIT EDGES:







tELL nO tALE jADE FROM bIG tOAD cREEK:


I guess it does have tells on it, but it is a great example of the way it hides, with several rind types plus creek scum. it also has an assortment of jade variety (white with chromiam green and standard mottled jade green with occassional chromiam specks) including a botryoidal knob. Depite the scum and rinds, truely one of my best finds...and I've only just started collecting at this locality. I do have samples of these rinds from other localities...including a great botryoidal with the white with chromian specks...that's why I can tell this is all jade and not half jade half grossular as grossular isn't botryoidal ever and the botty area on here is that stuff, the other side is the more traditional mottled green...however there is that white green speckled seam that may be hgg)...what is so special about this creek is the amount of good quality jade as opposed to mostly poor quality on other creeks (picked over maybe?) I took a lot of pics to show the locals asking me what to look for...so I apologize

FULL SLIDESHOW:(first 15 on slideshow are dry)
[s790.photobucket.com]



Four Dry shots (first 15 on slideshow are dry):





slight botryoidal habit here:


WET SHOTS:





















I have two more to show in the future...both extremely informative...and in a week or so I will be bringing down another variety of high quality "rodingite" that I had to hide in a pool at the bottom of a cascade because it was too heavy to carry down with what I already had...and it was late...and steep...OK...I was being a wuss...hope y'all enjoy!

what do you think of this material?
It is in the SG 2.9 and hardness range 6-7 of nephrite but the more yellowy material is not scratched by quartz. I call it serpentine at this point and am aware that there is some hard serpentine. Under high magnification I can see fuzzy, long fibrous material that looks like wool thread magnified; yes I know about asbestos and it's relation. even the black healing material in the fractures is hard.
I know this thread is pretty old but there are a lot of varieties of this material in the world and some of it is probably a pretty good grade.
Any comments or suggestions, analysis, are welcome
Lloyd

Finally. Rodingites are getting their due respect. Who doesn't love them even if they don't know what they are ?

Rodingites occur at many places in Washington State. We don't have any really good ones from a crystallized mineral specimen point of view, but we do have some drusy grossulars from the upper areas of Pressentin Creek in Skagit County, and some highly revered green diopside intergrown with white grossular locations North of highway 532 between Oso and Darrington. The exact locations are held close to the chest.

Bart