New data for anthoinite

[摘要] Based on electron microscopy, electron diffraction data and the flat layer specimen technique applied in clay mineralogy, the X-ray powder pattern of anthoinite was indexed and the unit cell parameters were calculated. The mineral is triclinic (pseudomonoclinic) with a0 = 9.51 Å, b0 = 9.23 Å, c0 = 13.05 Å, α = 93°20', ß = 120°00', γ = 88°20', V = 990 Å3. Single crystals of the mineral suitable for X-ray work have not been found. Density 5.06. Thermobalance run (speed 10° C/min.) expels all water at one step at 400°–545°C. The temperature of dehydration suggests the presence of OH rather than H2O in the structure. Two new chemical analyses are given confirming the composition AlWO3(OH)3. The number of anions in the unit cell is 60. Z = 10 for the formula given. The perfect cleavage suggests a crystal structure displaying sheets parallel to 001.