Locality: N. Sugarloaf Mtn. Bethlehem, NH
Specimen Size: 8 mm field of view. Tested mineral is resinous brown upper center and mid center.
Field Collected: Gene Bearss
Catalog No.: 2089
Notes: A carbon tape mounted grain EDS analysis BC288A, showed a Nb, Ta, U, Ca mineral. The tiny bit of Al is likely surface contaminent.
This specimen gives a weak response on my scintillometer.
Fred Davis contributed: "Not a super great fit for Ercit plot (it's missing lots of elements like Y, LREE, HREE, Ti, Pb, etc). But I plugged in the data and [generated this plot]. Suggested mineral is a pyrochlore (Ercit preceded the whole renaming debacle.) It does sorta fit with the old Handbook of Mineralogy data for uranpyrochlore. Nb-dominant pyrochlore is certainly better than microlite which is Ta-dominant."
Locality: Hurricane Mtn., Conway, NH
Specimen Size: About 3 mm FOV?
Field Collected: Bob Wilken
Catalog No.: A Bob Wilken specimen and photo
Notes: [bw] This is a greasy brown material.
EDS analyses indicated a pyrochlore species. With no Ca or Na in the analysis, the fluorplumbopyrochlore species is suggested.
Locality: Water Pocket, Blackberry Crossing, Albany, NH
Specimen Size: 4 mm earthy (weathered) Pyrochlore crystal. Zircon in background
Field Collected: Bob Janules
Catalog No.: 1711
Notes: Habit and color are consistant with other Conway granite pyrochlore specimens. Rocks & Minerals, Vol 65 No. 4, July-Aug 1990, pg 295 notes the Albany, NH occurrance found by Peter Samuelson, "Pyrochlore was found as octahedra up to 1.4 cm having a dull off-white surface and a brown-black interior, intergrown with zircon." This specimen was recovered from the dump pile Peter left behind. A Nov. 2012 Raman analysis of two points from a grain sample from this specimen reported: "good match to yttropyrochlore-(Y); fair match to ishikawaite (but two peaks only)". An EDXRF analysis gave a noisy, but usuable, spectra suggesting a niobate with less U and Fe than samarskite or ishikawaite.
[tm] This is the pyrochlore specimen in my New Hampshire minerals species display, Concord, NH.
Locality: Water Pocket, Blackberry Crossing, Albany, NH
Specimen Size: 9 mm field of view. Massive lustrous resinous brown pyrochlore surrounding unknown black mineral, perhaps columbite.
Field Collected: Tom Mortimer
Catalog No.: u2069 WP-1
Notes: It is impossible to avoid bright reflections with the conchoidal fractured pyrochlore.
A polished grain EDS analysis from this specimen showed a moderate amount of Fe. Iron is not present in pyrochlore group members. Only one IMA approved mineral contains Nb, Fe, and Ca : Latrappite, A second analysis from a different point on this grain gave EDS analysis 2. This analysis had no Ca. It is possible there is a zirconium peak (2.042 KeV) hiding next to the Nb peak (2.165 KeV).
The uranium content of this mineral is sufficient to enable prospecting and detection with Geiger counters and scintillometers. Zircon is a very frequent association.
Additional analysis is needed. What have we got here!
Fred Davis obtained some XRF data on this WP pyrochlore on 11/29/17. His assessment is:
[fd] "data was acquired in air on unpolished specimens; light elements are attenuated in air;
The dark, resinous anhedral "hot" material is primarily a niobate (with small amounts of tantalum), with uranium and small amounts of thorium (that makes it hot), Y and LREE. Looks like a pyrochlore group member....Treating the data as essentially qualitative, the major components are Nb, Ta, Fe, U and Ca. Minor components are V, Pb, Y, Th, Zr and Nd, and occasionally Sn and Ce. These appear in the pyrochlore group, but insufficient U to be the old "uranpyrochlore." Also, I didn't see Ti which is odd....Also, the redefinition of the pyrochlore group makes getting [a] specific [species] *much* more difficult."
Locality: Ledge above Water Pocket, Blackberry Crossing, Albany, NH
Specimen Size: 0.8 mm group of coated pyrochlore? crystals
Field Collected: Tom Mortimer
Catalog No.: u2069
Notes: These appear similar to the N. Sugarloaf Mtn. plumbopyrochlore crystals. The coating has chipped off a corner of the lower crystal.
Locality: Water Pocket, Blackberry Crossing, Albany, NH
Specimen Size: 2.2 mm pyrochlore crystal
Field Collected: Tom Mortimer
Catalog No.: u2076
Notes: This pyrochlore crystal was embedded in matrix
Locality: Water Pocket, Blackberry Crossing, Albany, NH
Specimen Size: 8 mm field of view - resinous-brown pyrochlore
Field Collected: Tom Mortimer
Catalog No.: u2104
Notes: Massive pyrochlore sampled for EDS analysis, BC268. This EDS analysis 3 was similar to a previous analysis, (#2), but clearly showed the expected calcium component. Some of the Na in the analysis may be from a carbon coating contaminant, but Na is indicated as a Ca substitite in the formula for pyrochlore.
Locality: Water Pocket, Blackberry Crossing, Albany, NH
Specimen Size: 17 mm field of view
Field Collected: Fred Davis
Catalog No.: TO651
Notes: Fred Davis obtained a XRF analysis on this WP specimen on 11/29/17. (big file/image to see detail)
[fd]"The "pyrochlore" was fair sized so I could use a 5mm aperture. You really have to zoom in to see the element IDs on the spectrum. Ignore stuff in the noise like Sr, Ac,Tm etc. The U wt % oxide I was seeing ranged between 4 ~ 5%, similar to your data which is why I said it was well below the 15 ~ 26% given for the old "uranpyrochlore."