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Parallel growth of columbite-(Fe) and samarskite-(Y)

 

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles


columbite samarskite Spinelli CT.jpg
columbite samarskite Spinelli CT full front.jpg
columbite samarskite Spinelli CT full back.jpg
ThereminoMCA_Amptek_DppMCA_Si-PIN_columbite-Fe samarskite-Fe Spinelli CT.png

 

Interesting report Charles. Such an analysis would be difficult by other means without destroying all or part of the sample?



George?

----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected], albinitony@...
Sent: Tue, 17 Mar 2020 09:44:54 -0400 (EDT)
Subject: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles
 

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Correct, George. While this type if analysis is not quantitative, you can get a good idea of what type of crystal(s) you are looking at. Microprobe analyses are quantitative, but require at least a small chunk of material for analysis. Attached is a picture of a sample mount for the microprobe, it is about an inch across. We have worked up quite a few of these for analyses at UNM.

Steve

From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...>
Sent: Tuesday, March 17, 2020 9:15 AM
To: [email protected] <[email protected]>
Subject: Re: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)
?
Interesting report Charles. Such an analysis would be difficult by other means without destroying all or part of the sample?



George?

----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected], albinitony@...
Sent: Tue, 17 Mar 2020 09:44:54 -0400 (EDT)
Subject: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles





Sample_Mount.png

 

Right.? Of course, it wasn't like I was discovering anything new.? If you follow the mindat link you can see that others have specimens with more distinct crystals of both types.? Without the analysis that other people did previously I would probably still be scratching my head (while keeping my hands away from my face of course).? My results do add to the body of evidence though.

Charles


On Tue, Mar 17, 2020 at 8:15 AM <GEOelectronics@...> wrote:
Interesting report Charles. Such an analysis would be difficult by other means without destroying all or part of the sample?



George?

----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected], albinitony@...
Sent: Tue, 17 Mar 2020 09:44:54 -0400 (EDT)
Subject: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles
 

¿ªÔÆÌåÓý

These types of associations are fairly common; attached are a couple of pictures of columbite associated with monazite - a Nb-Ta oxide intergrown with a REE-Th-phosphate. Pretty easy to tell these apart. We also see Ta-rutile overgrown on microlite and euxenite overgrown on columbite. Neat stuff.

Steve

From: [email protected] <[email protected]> on behalf of Charles David Young <charlesdavidyoung@...>
Sent: Tuesday, March 17, 2020 10:02 AM
To: [email protected] <[email protected]>; albinitony@... <albinitony@...>
Subject: Re: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)
?
Right.? Of course, it wasn't like I was discovering anything new.? If you follow the mindat link you can see that others have specimens with more distinct crystals of both types.? Without the analysis that other people did previously I would probably still be scratching my head (while keeping my hands away from my face of course).? My results do add to the body of evidence though.

Charles

On Tue, Mar 17, 2020 at 8:15 AM <GEOelectronics@...> wrote:
Interesting report Charles. Such an analysis would be difficult by other means without destroying all or part of the sample?



George?

----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected], albinitony@...
Sent: Tue, 17 Mar 2020 09:44:54 -0400 (EDT)
Subject: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles





Freetland_col-mon02.JPG
Red_Starship02.JPG

 

Yes, that's true, but I'm having fun in the same way, running down Trinitite peaks as reported from some of the best gamma spectroscopists in the world. I don't expect to add anything to their work, but am certainly adding a lot to my own knowledge base.

Still, once in a while I see a peak someone else labeled Pb- X-Rays that are unquestionably not exclusively that at all, but sum peaks from the very strong presence of Am-241 peaks.

I'm still working on the presence of Ba-133 in Trinitite, because of the short half life. Ditto Co-60. My own Spectech disc sources that I bought in 2002 and 2003 have all but run out already......There is a lot of barium in there, but not necessarily a radioactive species.?

Another angle is the high quantity of Strontium present (by XRF not by Gamma Spec alone). Sr-90 should be present in similar quantities compared to Cs-137 I think.

The real exciting thing is identifying several species of plutonium, that's a hoot for me.

Geo>K0FF

.

----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected], albinitony@...
Sent: Tue, 17 Mar 2020 12:02:15 -0400 (EDT)
Subject: Re: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

Right.? Of course, it wasn't like I was discovering anything new.? If you follow the mindat link you can see that others have specimens with more distinct crystals of both types.? Without the analysis that other people did previously I would probably still be scratching my head (while keeping my hands away from my face of course).? My results do add to the body of evidence though.

Charles

On Tue, Mar 17, 2020 at 8:15 AM <GEOelectronics@...> wrote:
Interesting report Charles. Such an analysis would be difficult by other means without destroying all or part of the sample?



George?

----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected], albinitony@...
Sent: Tue, 17 Mar 2020 09:44:54 -0400 (EDT)
Subject: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles
 

I've seen some of your microprobe reports, and they are amazing. If I was still a kid I would be on my way to U of NM right now......but alas, I'll have to be satisfied with the reactor operators school here? and the countries largest research reactor....


Geo

----- Original Message -----
From: WILLIAM S Dubyk <sdubyk@...>
To: [email protected]
Sent: Tue, 17 Mar 2020 12:01:58 -0400 (EDT)
Subject: Re: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)


Correct, George. While this type if analysis is not quantitative, you can get a good idea of what type of crystal(s) you are looking at. Microprobe analyses are quantitative, but require at least a small chunk of material for analysis. Attached is a picture
of a sample mount for the microprobe, it is about an inch across. We have worked up quite a few of these for analyses at UNM.


Steve


From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...>
Sent: Tuesday, March 17, 2020 9:15 AM
To: [email protected] <[email protected]>
Subject: Re: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)
?
Interesting report Charles. Such an analysis would be difficult by other means without destroying all or part of the sample?



George?

----- Original Message -----

From: Charles David Young <charlesdavidyoung@...>

To: [email protected], albinitony@...

Sent: Tue, 17 Mar 2020 09:44:54 -0400 (EDT)

Subject: [XRF] Parallel growth of columbite-(Fe) and samarskite-(Y)

I have an interesting specimen from the Spinelli Prospect in CT.? It is similar to other specimens reported from this locality.


Even though this appears to be one solid crystal there is a distinct difference from front to back.? The front is a subhedral columbite-Fe crystal with distinct faces.? The back not so much.? Along the edge there is a fracture that transitions from hackly
to conchoidal as it goes from columbite to samarskite.? Finally, my XRF of both sides shows that the columbite has no Y to speak of whereas the samarskite side has lots of it.

Many of my specimens are mixtures of minerals but usually not so distinct.

Charles

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