Ryan's big long mega post of ID's needed!

[Ryan]

Hello all,
I have a few pieces from my summer travels in your fine state that I need help with. I was hoping to get these ID’ed by some of you that obviously would know your own state’s geology better than I. As I’ve mentioned before, my company sends me to various NC towns and cities quite frequently (at least 2x a month). I almost always make time for some rockhounding. Sometimes (err…most times) I take things home that I can’t quite fully identify.

This first one was collected at the new NC-321 road-cut out of Blowing Rock towards Lenoir. The rock there appears to be coarse-grained gneiss interlaced with quartz veins and some small intermittent dark black patches of material. I go here for the pyrite cubes in matrix with veins of purple massive fluorite. The contrast of the gold and purple on dark grey rock make for nice hand specimens. Usually they (the pyrite cubes) are speckled in the gneiss and range from micro to about a half inch. Sometimes they are quite densely packed together.

Last time though, I went a bit further down the road-cut to explore and found a whopper cube cluster (largest was ¾ inch with a ½ inch twin and some babies, huge for the locale). In the same general area, I also found a chunk of this other material. I am not sure what it is. It reminds me of the massive calcite and/or platy barite we get up here in my neck of the woods, but the color sort of reminds me of dolomite I get in NY. Here are two pictures. The one has yellow arrows pointing to the mineral in question. The host rock is much lighter in color than most of what is around in this area. My best guess on this one is massive Calcite or Barite but, due to limited experiences in the field of North Carolina geology, my best guesses are often wrong. Can anyone identify?




Also from this same site, the black grainy stuff. There is, what appears to be, dark grey / black slate in this area, but this black stuff is a totally different material. It’s rather shiny and very dark black. It occurs infrequently in the gneiss and looks strangely menacing. I have this weird fear that it is radioactive. Anyone have any ideas?



Ok! Let’s go across the state to Wake Co. Next up, we have this black pebble. I was meeting Joe and Scott for a day of digging quartz in Chatham Co. and had some time to kill in the Raleigh area the day before. Joe had mentioned that panning and digging around in the stream behind the Art Museum might be a good place to kill some time. I found some agate and some crappy quartz specimens, and then I found this. It’s really light for its size and was unique in the surrounding gravel. It looks like coal, but I am fairly certain it isn’t coal. It’s harder. The bituminous coal from here in Western PA is softer and has a different luster. I showed Joe and he said to hang on to it. He said he wasn’t sure what it was either, so if anyone wants to wager a guess, here it is from two angles. This piece measures in at about an inch.



Up to the PA / Jersey border! Next up is a Calcite specimen I received in a trade from another MAGMA member. I believe the piece’s origin is Eastern PA or New Jersey and I know (as per the trader’s hand-written label) the clear crystals are Calcite. What puzzle me are the radiating spirals and the cubes. They appear to be very similar in appearance aside from crystal habit. They are both white, somewhat glossy and react the same in Long Wave UV. In one spot on the specimen, you can see where the radiating sprays almost look like they’re morphing into the cube habit.

My questions on this piece are, what are they and/or are they two habits / growth stages of the same mineral or not. Perhaps the same mineral in natural form and pseudo morph form? (Some mineral after fluorite for the cubes?) I have the piece photographed in both LED White Light and in LWUV light. Any ideas?




Lastly, I have this amethyst point that I was looking at the other day. I picked it up last winter at the Silver Armadillo. (I just cannot leave North Carolina without bringing SOMETHING rock related home )

The surprising part was discovered when I tried to remove what appeared to the naked eye to be dirt on the crystals face. I tried to rub it off with a Kleenex to no avail so I got out the loupe. To my surprise, it appeared to be little radiating needles of an orangey-yellow mineral. I think this is Cacoxenite. The only reason I know of its existence is from reading Ricks MAGMA webpage on Diamond Hill minerals. Can anyone confirm?

From what I read, this is a rare phosphate mineral? It is sooo tiny on this specimen that I had to backlight the crystal in order to get a decent picture of it. In the third photo, I held the camera up to my 10x loupe to get a close-up and then used some Photoshop magic to make a little window in the corner of the image. This helps to show the crystal structure.




Thank you all in advance for reading this and I hope some of you can help me figure out the first three and confirm my ID of Cacoxenite on the Ammy. I hope to see/meet a lot of you at the DH dig next week! Wooo!

[DigDug]

Your with-w/o flash photos, thats gemmy feldspar stufff, I have some from the same road consturction they were doing on 321. No radioactivity I am aware of...lol, I hope not, I have a whole bunch in the basement. I have used the pyrite, have not done anything special with the feldspar.

[Ryan]

Dude that cab is SWEET. Im looking for an ID on the black crusty stuff though, theres three patches of it on top of the stone. Is that what you were talking about?

[arappaho]

Man, Dug, that is a killer cab! I'd like to see that in person, and
see a piece of the rough! Got any more?

Hey Ryan,
That pinkish stuff in the first set of pics does look like feldspar. Not
sure what field test to try on it.
I'm going to have to guess Old Molly on the metallic black "grainy"
looking stuff in the second specimen. Molybdenite that is.
Hardness 1-1.5. Streak, gray-black, to greenish on white porcelain.
And I'd say run the same test on the black piece from behind the
museum in Raleigh. If it's not moly, it's got to be Ilmenite.
Ilmenite hardness 5-6, streak black, but it's weakly magnetic. It
ought to make the needle on a compass move slightly.

Have to agree with the cacoxenite in the amethyst, too.

Great pictures all. Well done. Thanks for the post.
Joe

[DigDug]

Yes, I have plenty of the pyrite in host stone.

[Ryan]

I too have some of that I can send you Joe. If youre out towards Watauga/Caldwell Counties, just stop on the side of the highway on the way down from the blowing rock, they "shaved" off a few thousand tons of mountain and just dumped it over the side. The top and middle of the new road have pyrite. Not much of interest at the bottom though.
Thanks Joe and DigDug for yer two-bits. Molybdenite sounds about right. I checked and its pretty soft and brittle. Im not 100% convinced on the feldspar diagnosis but y'all would know better than I. The little black pebble is still a mystery and the ammy with (crappy and small) cacoxenite seems to fit.
Anyone care to wager a guess on the white stuff on the calcite specimen?

[Ryan]

Thanks Earthnhands, I dunno about Kyanite either. I have a lot of kyanite and its not quite the same. This is smooth, platy, and seems to fracture very clean forming a sqared off edge. It is on the contact of the country rock and the quartz. Perhaps it formed afterwards? Here's one more close-up. This is taken under plain old incandescent room light and the pic actually turned out very "true" to color. Typically my cameras skew color a bit. I know if there's a group of folks who can ID this stuff, its MAGMA! Also, still looking for help on the Calcite specimin! What are those little white cubes! Thanks to all who answerd so far! You guys rock.

[41dave]

no expert...but... the NC stuff..

#1 Calcite...have you checked it under a UV? not that all calcite glows but if it does, there's your answer....but I would agree with your initial ID of it being calcite.

#2 Biotite-rich schist coating...much like what you see at the Crabtree.

#3 Coal..if its light enough to the point you can describe that it being light is a distinguishable characteristic, I have to lean towards coal.

The PA/NJ piece...sure looks like New Street Quarry material...

my guess is Analcime
www.mindat.org/gallery.php?cform_is_valid=1&loc=5400&cf_pager_page=1

dolomite is another guess.

and 100% on the cacoxenite in the amethyst, actually pretty common in Brazil stuff I think.

-Dave

[Ryan]

Thanks Dave! I though the first one looked familiar. We have clay-ironstone concretions in the shale up here in Pa that have platy calcite and barite just like the NC-321 specimin. I hunt those because the clacite and barite sometimes are home to spalerite and wurtzite micro specimins. No glow under LWUV and I dont own a SW so I wont know until I buy one.

UPDATE: I was messing around with the little black pebble and tried to scratch it. The tip fractured off and turned to powder. So I now feel strongly that it is plain old coal. Didnt know you guys had coal! You learn something new every day.

Anyways, Im cataloging all my finds for the year and now feel confident in the IDs of all but the calcite crystals with the white cubes and sprays and the crusty black stuff in chunk 2. Your guess of Anaclime or Dolomite is pretty good Dave, Im checking Mindat now and it seems like a good probability. Is that two different minerals, crystal habits of same thing, or diff stages of development of same stuff remains the only question on that one. Everyone said something different on the black stuff from 321 so its up in the air. Not a stellar piece though so im not too terribly concerned. Thanks again man!

[Ryan]

UPDATE. Thanks to Dave's link to mindat.org, I have IDed the little white sprays as Laumonite. Great call on the New Street Locale. The trader was a member from Jersey so that's most likely the origin.
I think there is one large lump of Anaclime. The Anaclime lump glows in the UV while the Laumonite does not. Otherwise I would have thought they were the same thing. The cubes are still confusing me. But I noticed siderite on the New Street Quarry's local mineral list. could the Laumonite have replaced the Siderite? That would make for a chalk white color but retain the cubic form of siderite right? Not sure if that pseudomorph is even possible but its all I got :/

[41dave]

Ryan,

keep in mind all 50 states have coal, non-native variety. Coal was used so much in factories/mills around the country, it been on every rail-line in the country. Every piece of matter that has weight wants to find the lowest point possible, those points naturally being streams.

So your coal is probably from PA or WV or KY, and it made its way to NC on a rail and hit a bump and out it fell, tumbling down into the river.

-Dave

[Ryan]

HAhahaha, and now its back home in Western PA. Amazing

[lauriesrocks]

I largely agree with Dave. First one is definitely calcite-yes, check for fluorescence. Second one-biotite. The black piece looks like coal, just wonder how light weight it is. I would guess hematite or ilmenite if it wasn't so light. The zeolite piece-radiating crystals I think are pectolite, but I can't be positive without seeing the specimen in person. Laumontite tends to be less acicular in form and not as radiating. Of course when exposed to air it is technically leonhardite, because it loses it's water and thus changes chemical composition, becoming a new mineral. (Just like torbernite becomes meta-torbernite for the same reason) If it is laumontite, it will probably disentegrate pretty soon. Laumontite would be very soft, so that you could rub the crystals right off the specimen with your finger, while pectolite tends to be pretty hard in comparison. Cubes are probably apophyllite, a common cubic accessory mineral from the New Jersey trap quarries. Analcime rarely forms cubes, they typically form trapezohedral crystals, particularly in NJ. Last one is definitely cacoxenite.

[hydrogeologist]

I agree with laumontite, it looks exactly like the laumontite sprays I have on several New Street pieces. It is soft enough to rub off by touch and should be handled delicately, if at all.

[carnelianpete]

Ryan,
I am sorry I did not find this thread sooner. You got that piece from me it looks like. I did a lot of trades a while back. It is definitely calcite with laumontite and apophyllite. That could be a analcine xl on the end but it looks a little beat up. The piece, as mentioned, is from the Upper New Street Quarry in West Paterson NJ. It was collected in the spring of '09. That is when I hit several seam pockets that were all the same type of combo pieces. If you are interested I may have a analcine specimen or two around and would be more than happy to trade them with you. PM me if you are. These are in much better shape than the xl on that piece.

I can make one suggestion on preserving the laumontitie. Get a can of Jewelry Mold Release Spray. It is a pure silicone spray and I use it just for this purpose. It will put a very fine coating on fragile specimens and hold them together while protecting them from falling apart. It works very good and does not impart a shinny coating on the specimen.

Note: when purchasing specimens check the piece real well. Some dealers spray the specimens before sale to give them that little extra kick to make them look better. I have seen it where they over did it and you could see drips of the stuff running down the side of the xl.

Pete

[JohnD]

I walk the shore of Lake Hartwell and find tourmaline in different sizes and shapes. Your black specimen looks like some small chunks or pieces of tourmaline broken away from a massive piece.

[Ryan]

Thanks Pete and John. That was very helpful Pete, I appreciate the input. And John: I thought the same about the black piece, but when I attempted a streak test, the end crumbled just like coal. So I made the deduction that it indeed was just that, a little chunk of coal. Funny, that I live in an area that is sitting on millions of tons of coal and I bring a chunk home to PA thinking it was something special. You'd think Id know better! ( Having lived on top of tons of coal all my life)

Everyone has been so helpful and knowlegable. The only one in my post that Im still not sure of is the black crust on the gniess. Ive heard biotite, molybdinum, and a few others. Its not a spectacular piece though, so Im not to concerned with it.
Thanks to all who gave their input