Locality: Palermo #2 Mine, N. Groton, NH
Specimen Size: 3 cm specimen. Red arrow points to small vug containing collinsite.
Field Collected: Jim Nizamoff
Catalog No.: u2080
Notes: A photo to show the complete specimen.
Locality: Palermo Mine, N. Groton, NH
Specimen Size: 4 mm field of view.
Field Collected: Dana Jewell - April 1999
Catalog No.: u2112
Notes: Dana gave me this in October 2017. He had it labeled fairfieldite. As I have found Palermo fairfieldite to be very rare, I wanted an EDS confirmation. Two separate EDS grain analysis were done, two probings each. The BC253 analyses were grains on carbon tape, the BC234 analyses were polished grain. A moderate variation in chemistry was observed. The APFU's were calculated normalizing for two atoms of Ca. The oxygens were not grouped with P and H, as this cannot be determined by EDS.
BC253a => Ca2(Mg0.6,Fe0.4,Mn0.13)P2.87O40.8 This was best analysis, count peak value = 1100.
BC253 => Ca2(Fe1.22,Mn0.42)P2.04O32.4 . Mg response seen in plot but was not quantified by
software. Small Al, Si, K likely feldspar contaminant. Count peak value = 300.
BC234 => Ca2(Mg0.48)P3.15O31.9 Peak count value = 297.
A Fe response was on the plot, but not quantified.
BC234a => Ca2P3.74O48.3 . Mg & Fe responses seen in plot but were not quantified by
software. Count peak value = 342.
The Handbook of Mineralogy gives a collinsite analysis of
Ca1.92(Mg0.78,Fe0.34)Σ=1.12P1.95O9.6 and the ideal chemistry as: Ca2(Mg,Fe)(PO4)2 · 2H2O