Wooldridgeite, ideally Na 2 CaCu 2 (super 2+) (P 2 O 7 ) 2 (H 2 O) 10 , orthorhombic, a = 11.938(1), b = 32.854(2), c = 11.017(1) Aa, V = 4321.2(8) Aa 3 , a:b:c = 0.3634:1:0.3353, space group Fdd2, Z = 8, is a new mineral from Judkins Quarry, Nuneaton, Warwickshire, England. Associated minerals are calcite, chalcopyrite, bornite and baryte. It occurs as equant crystals forming rhombic dipyramids; no twinning was observed. It is transparent blue-green with a very pale-blue streak, a vitreous lustre, and does not fluoresce under long- or short-wave ultraviolet light. Wooldridgeite has a Mohs hardness of 2-3, is brittle with an irregular fracture, and has no cleavage. The calculated density is 2.279 g/cm 3 . In transmitted light, wooldridgeite is colourless, non-pleochroic, and shows no dispersion. It is biaxial negative with alpha = 1.508(1), beta = 1.511(1), gamma = 1.517(1), 2V(meas.) = 76.2(5), 2V(calc.) = 71(10) degrees , X = b, Y = c, Z = a. The strongest five reflections in the X-ray powder diffraction pattern are [d(Aa), (I), (hkl)]: 8.23(30)(040), 6.52(100)(131), 4.05(40)(260), 3.255(40)(262); 2.924(40)(371). Electron-microprobe analysis of wooldridgeite gave P 2 O 5 39.37, CuO 20.24, MgO 0.24, CaO 7.73, Na 2 O 8.33, K 2 O 0.17, H 2 O(calc.) 24.72, sum 100.80 wt.%; the corresponding unit formula (based on 24 anions) is (Na (sub 1.96) K (sub 0.03) )Ca (sub 1.00) (Cu (sub 1.85) Mg (sub 0.04) )P (sub 4.04) O 14 (H 2 O) 10 where the H 2 O groups were assigned from knowledge of the crystal structure; the infrared absorption spectrum also indicates the presence of H 2 O in the structure. The mineral is named for James Wooldridge (1923-1995), a fervent amateur mineral collector who discovered this mineral.

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