抄録
Garronite occurs as radiating aggregates of minute fibrous crystals in amygdales of altered trachybasalt from Kuniga, Oki Islands, Shimane Prefecture, Japan. The mean chemical composition by EDS analysis leads to the empirical formula, (Na1.15K0.15)Σ1.30Ca2.28 [Al5.88Si10.06]O32·13.60H2O on the basis of O=32 in anhydrous part and H2O by difference. The unit cell parameters calculated from the X-ray powder diffraction data are a = 9.961 (3), b = 10.178 (4), c = 9.958 (4) (Å) and β = 90.020 (1) (°) with a monoclinic cell.
