Locality: Palermo Mine, N. Groton, NH
Specimen Size: 1.8 cm specimen with powdery green mitridatite coating
Field Collected: Tom Mortimer
Catalog No.:
Notes:
Locality: Palermo Mine, N. Groton, NH
Specimen Size: 8 mm field of view. Powdery green mitridatite coating rhombic siderite crystals.
Field Collected: Tom Mortimer
Catalog No.: TBC
Notes:
Locality: Palermo #1 Mine, Pod 3, N. Groton, NH
Specimen Size: 4 cm specimen with zones of massive, olive-green, mitridatite
Field Collected: Forrest Fogg - from flat of unlabeled Fogg specimens from Gordon Jackson
Catalog No.: 1893
Notes: Mitridatite is much more common at Palermo as a dusty, olive-green, coating on other phosphate and carbonate minerals. A qualitative EDS analysis of this specimen implied a Ca predominant Fe phosphate that (chemically) suggested the massive form of xanthoxenite, Ca4Fe3+2(PO4)4(OH)2 · 3H2O, although this specimen would be visually excessively green for this species. However, when the substantially lower EDS detector response at 6.5 KeV vs. 4 KeV was factored in, Fe was likely greater than Ca in my sample. A follow-up XRD analysis gave an excellent match for mitridatite, Ca2Fe3+3(PO4)3O2 · 3H2O .
I am uncertain as to how common this massive form of mitridatite is at Palermo. I had not noticed it previously. Perhaps it is just over-looked.
The hardness measured about 3 with a commercial hardness point set.
Locality: Parker Mtn. Mine, Center Strafford, NH
Specimen Size: 5 mm vug with mitridatite coating
Field Collected: Gene Bearss
Catalog No.: A Gene Bearss specimen
Notes:
Locality: Palermo Mine, N. Groton, NH
Specimen Size: 5 mm field of view. Concentric spheres of mitridatite
Field Collected: From a box of small rock chunks gifted by Bob Whitmore
Catalog No.: u1527
Notes: This mitridatite presentation is quite unusual.
Locality: Chickering Mine, Walpole, NH
Specimen Size: 4 mm field of view
Field Collected: Tom Mortimer
Catalog No.: u1733
Notes:
Locality: Turner Mine, Marlow, NH
Specimen Size: 1.5 mm field of view
Field Collected: A Bob Wilken specimen & photo
Catalog No.: TUR01AS
Notes: [tm] Robertsite, the Mn analog of mitridatite, should also be considered here.
Locality: Palermo Mine, N. Groton, NH
Specimen Size: 4.5 mm field of view.
Field Collected: From a tub of Palermo phosphate rocks gifted by Bob Whitmore.
Catalog No.: u2444
Notes: The black balls are rockbridgeite. From a stack of 115 images with EPO lens.
Locality: Palermo Mine, N. Groton, NH
Specimen Size: 3.5 mm field of view
Field Collected: Bob Whitmore - from a tub of Palermo phosphate rocks gifted by Bob.
Catalog No.: u2446
Notes:
Locality: Palermo Mine, Groton, NH
Specimen Size: 6.8 mm field of view
Field Collected: Bob Wilken
Catalog No.: Bob Wilken specimen and photo
Notes: An EDS analysis, normalized for 4 Fe, gave Ca1.51Fe4.0P2.14O16.5. The material tested was the concentrically-ringed greenish-brown mineral. Bob gave consideration to a dufrenite ID.
Dufrenite chemistry is: Ca0.5Fe2+Fe3+5(PO4)4(OH)6 · 2H2O . The analysis of this specimen is a poor fit for dufrenite. The best IMA match is mitridatite.