Abstract: Both Species were Found as post-Mine Minerals in the Lone Pine mine, Catron County, New Mexico. They occur encrusting ores of fluorite-pyrite with khademite and gypsum.

Wilcoxite is clear, colourless to white, H = 2, D = 1.58. Abundant as spongy masses of perfect to somewhat rounded crystals. Stubby prisms are bounded by {100}, {010}, {110}, {¯110}, and {0¯11}. Triclinic P¯1 or P1 with a = 14.90, b = 6.65, c = 6.77 Å, α = 117° 26′, β = 100° 35′, γ = 80° 10′, and Z = 1. Strongest lines are 5.654(9) 110, 11¯1, 4.908(10) 1¯1, 4.371(6) 201, 210, and 3.384(5) 11¯2, 111. Biaxial negative with α = 1.424, β = 1.436, γ = 1.438, 2V_α = 48°. Analysis gave MgO 6.61%, Al₂O₃ 8.13, Fe₂O₃ 0.46, MnO 0.13, SO₃ 27.50, H₂O 56.40, F 3.48, total 101.24 (corr. for O ≡ F) leading to MgAl(SO₄)₂F·18H₂O.

Lannonite is usually as chalky white aggregates of microscopic tetragonal (square) platelets; H = 2, D = 2.22. Indexed as tetragonal a = 6.84, c = 28.01 Å, and Z = 1. Strongest lines are 13.98(10) 002, 4.840(7) 110, 3.980(5) 116, and 3.456(7) 017. Uniaxial positive with ω = 1.460 and ε = 1.478. Analysis gave CaO 12.06%, MgO 4.46, Al₂O₃ 11.06, SO₃ 34.40, H₂O 32.00, F 9.44, total 99.45 (corr. for O ≡ F) leading to HCa₄Mg₂Al₄ (SO₄)₈F₉·32H₂O.

Both minerals and mineral names have been approved by the Commission on New Minerals and New Mineral Names, IMA.

New analytical data for the khademite associated with these species are presented.