Fluoro-aluminoleakeite, ideally (A)Na(B)Na(2)(C)(Mg(2)Al(2)Li)(T)Si(8)O(22)(W)F(2), is a new mineral of the amphibole group from Norra Karr, Sweden(IMA-CNMMNC 2009-012). It occurs in a proterozoic alkaline intrusion that mainly comprises a fine-grained schistose agpaitic nepheline-syenite (grennaite). Fluoro-aluminoleakeite occurs as isolated prismatic crystals 0.10-2 mm long in a syenitic matrix. Crystals are light greenish-blue with a greenish-blue streak. It is brittle, has a Mohs hardness of 6 and a splintery fracture; it is non-fluorescent with perfect {110} cleavage, no observable parting, and has a calculated density of 3.14 g cm(-3). In plane-polarized light, it is pleochroic, X = pale green, Y = dark green, Z = pale green; X boolean AND a = 62.9 (in beta obtuse), Y parallel to b. Fluoro-aluminoleakeite is biaxial negative, alpha = 1.632(1), beta = 1.638(1), gamma = 1.643(1); 2V(obs.) = 98.0(4)degrees, 2V(calc.) = 95.5 degrees. Fluoro-aluminoleakeite is monoclinic, space group C2/m, a = 9.7043(5) angstrom, b = 17.7341(8) angstrom, c = 5.2833(3) angstrom, beta = 104.067(4)degrees, V = 882.0(2) angstrom(3), Z = 2. The eight strongest X-ray diffraction lines in the powder-diffraction pattern are [d in angstrom, (I), (hkl)]: 2.687, (100), ((3) over bar 31, 151); 4.435, (80), (021, 040); 3.377, (80), (131); 2.527, (60), ((2) over bar 02); 8.342, (50), (110); 3.096, (40), (310); 2.259, (40), ((1) over bar 71, (3) over bar 12) and 2.557, (30), (002, 061). Analysis, by a combination of electron microprobe and crystal-structure refinement, gives SiO(2) 58.61, Al(2)O(3) 7.06, TiO(2) 0.32, FeO 3.27, Fe(2)O(3) 6.05, MgO 8.61, MnO 0.73, ZnO 0.43, CaO 0.05, Na(2)O 9.90, K(2)O 2.43, Li(2)O 1.62, F 3.37, H(2)O(calc.) 0.50, sum 101.08 wt.%. The formula unit, calculated on the basis of 24 (O, OH, F, Cl) p.f.u. with (OH) + F = 2 a. p.f.u., is (A)(Na(0.65)K(0.43))(Sigma=1.09)(B)(Na(1.99)Ca(0.01))(Sigma=2.00)(C)(Mg( 1.77)Fe(0.38)(2+)Mn(0.09)Zn(0.04)Fe(0.63)(3+)Al(1.16) Ti(0.03)Li(0.90))(Sigma=5.00)(T)Si(8.00)O(22)(W)(F(1.47)OH(0.53))(Sigma= 2.00). Crystal-structure analysis shows (C)Li to be completely ordered at the M(3) site, and provided reliable site populations. Fluoro-aluminoleakeite is related to the end-member leakeite, (A)Na(B)Na(2)(C)(Mg(2)Fe(2)(3+)Li)(T)Si(8)O(22)(W)(OH)(2), by the substitutions (C)Fe(3+) --> (C)Al and (W)F --> (W)(OH).