Hühnerkobelite crsytals from the palermo no. 1 pegmatite, North Groton, New Hampshire

Single crystals and granular greenish-black masses, emerald green in transmitted light, of huhnerkobelite have been found in moderate abundance at the Palermo No. 1 Pegmatite, North Groton, New Hampshire, associated with numerous other phosphates.

Palermo hühnerkobelite is biaxial (+), α=1.727±.005 and γ= 1.738±.003, markedly pleochroic with X tan and Z blue-green. The crystals are monoclinic 2/m, short prismatic along [010] or [001], give morphological a:b:c = 0.872:1:0.527. The structure cell gives a: b: c = 0.868:1:0.515, a = 10.89, b = 12.54, c = 6.46 Å and β=97°33′.

This is the first reported occurrence of single crystals of huhnerkobelite and the first known occurrence of that mineral in the eastern United States.