Summary: Ruizite is a new mineral found in the mesogene calc-silicate assemblage at the Christmas mine, Gila County, Arizona. Occurs with kinoite, apophyllite, smectite, and junitoite. Colour is orange inclining to brown with pale streak, H = 5, Sp. Gr. meas. = 2·9. Crystals monoclinic 2/m, elongate on [010]; a = 11·95 Å, b = 6·17, c = 9·03, β = 91° 2212′. Probable space group P2₁/c with Z = 4 giving D_calc = 2·997. Strongest lines are 11·951 Å(10), 4·190 (7), 3·116 (6), 5·092 (5), 3·644 (4), 2·951 (4), 2·591 (4), 2·132 (4). Indices are α = 1·663, β = 1·715 ‖ [010], γ = 1·734, 44° to [001] in obtuse β; 2V_α = 60·2°; inclined dispersion p > v strong. Twinned on {100}. Analysis by wet methods gave CaO = 20·57%, Mn₂O₃ = 23·42, SiO₂ = 39·14, H₂O = 16·0 leading to Ca1·06Mn0·863+(SiO3)1·89(OH)1·032·06H2O or CaMn³⁺ (SiO₃)₂(OH). 2H₂O.

Named for its discoverer, Joe Ana Ruiz of Mammoth, Arizona