Baileychlore occurs as dark green rims on colloform calcite veins within a strongly oxidized collapse karst-breccia containing altered andesite and garnet-vesuvianite skam clasts at the Red Dome deposit near Chillagoe, Queensland, Australia. Baileychlore is a new Zn-rich chlorite. The ZnO contents are fairly uniform from 28.2 to 30.5 wt% at a depth of 89.6 m in the deposit, with a structural formula of (Zn2.50Fe1.202+Al1.17Mg0.76Mn0.012+0.36)(Si3.55Al0.45)O10(OH)8 for the most Zn-rich analysis. The name is for Professor Sturges W. Bailey of the University of Wisconsin and is to be used for any trioctahedral chlorite in which Zn is the dominant divalent octahedral cation.

Baileychlore occurs as fine-grained transverse fibers exhibiting zoned pleochroic colors (green to yellow-green) along their length. Refractive indices are α = 1.582 and γ = 1.614. The measured and calculated densities are 3.18(2) and 3.195 g/cm3, respectively. Combined dta-tga curves show a major endotherm at 550 °C, a small, double-bottomed endotherm in the range 680-750 °C, and an exotherm at 850 °C. The X-ray powder pattern is that of the Ib (β = 97°) polytype. The strongest lines (24 given) are [dobs(Iobs)(hkl)] 14.3(90)(001), 7.14(100)(002), 4.600(30)(02; 11), 3.573(40)(004), 2.660(50)(201,130), 2.450(35)(203,132), and 1.542(60)(060,331). Unit-cell dimensions are a = 5.346(3), b = 9.257(4), c = 14.401(7) Å, and β = 97.12(5)°. The symmetry is probably triclinic C1 or C1 because of semi-random stacking. A one-dimension electron-density projection and an asymmetry value of +1.29 suggest a composition ((Zn2.50Al0.140.36)0.58− for the octahedral sheet within the 2:1 layer and (Fe1.202+Al1.03Mg0.76Mn0.012+)1.03+ for the interlayer sheet.

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