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Cuprozheshengite, Pb4CuZn2(AsO4)2(PO4)2(OH)2, is a new mineral species from Yunnan, China. It occurs as sub-millimeter greenish-blue hemispherical aggregates of microscopic blade-like crystals on hemimorphite and is closely associated with veszelyite and galena. Cuprozheshengite is brittle with irregular fracture and has a Mohs hardness of 2½–3 and perfect cleavages on {011}. The calculated density is 5.91 g/cm3. The empirical chemical formula of the holotype is (Pb3.97Na0.04Ca0.01)Σ4.02Cu1.06 Zn2.09(AsO4)2[(P0.84As0.12Si0.01)Σ0.97O4]2(OH)2 based on 18 O atoms per formula unit. Cuprozheshengite is triclinic, space group P 1 , with unit-cell parameters a = 4.7977(8), b = 8.5789(8), c = 10.3855(9) Å, α = 97.270(8)°, β = 101.902(12)°, γ = 91.495(11)°, V = 414.30(9) Å3, and Z = 1. Cuprozheshengite is a member of dongchuanite group, whose general formula is A4VIBIVB2(X1O4)2(X2O4)2(OH)2, where A is an interlayer cation with Pb being dominant; B are transition metals with two crystallographic positions, IVB has tetrahedral coordination and is fully occupied by Zn, while VIB has octahedral coordination and is dominated by Zn or Cu; X1 and X2 are cations with tetrahedral coordination, occupied by As and P. Like other dongchuanite group minerals, the structural framework of cuprozheshengite is composed of two heteropolyhedral columns along [100]. Type 1 columns comprise corner-linked [IVBO4] and [X2O4] tetrahedra. Each tetrahedron is connected with three other tetrahedra in the columns. Type 2 columns have alternating [VIBO4(OH)2] octahedra with pairs of corner-connected [X1O4] tetrahedra. These two columns are connected by corner-sharing between [IVBO4] and [X1O4] tetrahedra to form layers parallel to (011). Pb atoms occupy two independent sites between the layers. Cuprozheshengite is named as the copper analog of zheshengite. Single-crystal X-ray diffraction reveals that As and P order over the X1 and X2 sites, with As tending to occupy X1. Density functional theory (DFT) calculations confirm the occupancy propensity of As benefiting structural stability. The structural and stability studies of cuprozheshengite may have implications for local environmental governance. As a stable mineral in the water and elemental cycles after weathering, cuprozheshengite still has the potential to continually crystallize, fixing As into a stable crystalline waste form. [ABSTRACT FROM AUTHOR]

Hydroxylbenyacarite, (H2O)2Mn2(Ti2Fe)(PO4)4[O(OH)](H2O)10⋅4H2O, is a new paulkerrite-group mineral from the El Criollo mine, Cordoba Province, Argentina (IMA2023–079). It was found in specimens of altered triplite, in association with bermanite, phosphosiderite, quartz, strengite and manganese oxides. Hydroxylbenyacarite occurs as light greenish-yellow rhombic tablets with dimensions of typically 20 to 50 μm, occasionally to 400 μm. The crystals are flattened on {010}, slightly elongated on [001] and bounded by the {111} and {010} forms. The calculated density is 2.32 g cm–3. Optically, hydroxylbenyacarite crystals are biaxial (+), with α = 1.608(3), β = 1.624(3), γ = 1.642(3) (measured in white light) and 2V(meas.) = 88(2)°. The calculated 2V is 87.5°. The empirical formula is Ca0.06A [K0.46(H2O)0.88□0.66]Σ2.00M1(Mn1.52Mg0.02Fe2+0.35□0.11)Σ2.00M2+ M 3(Fe3+1.21Al0.02Ti1.77)Σ3.00(PO4)4X [F0.16(OH)0.70O1.14]Σ2.00(H2O)10⋅3.77H2O. The average crystal structure for hydroxylbenyacarite has space group Pbca and unit cell parameters a = 10.5500(3) Å, b =20.7248(5) Å, c = 12.5023(3) Å, V = 2733.58(12) Å3 and Z = 4. It was refined using single-crystal data to wRobs = 0.074 for 2611 reflections with I > 3σ(I). The crystal structure contains corner-connected linear trimers of Ti-centred octahedra that share corners with PO4 tetrahedra to form 10-member rings parallel to (010). K+ cations and water molecules are located in interstitial sites within the rings. Additional corner-sharing of the PO4 tetrahedra with MnO2(H2O)4 octahedra occurs along [010] to complete the 3D framework structure. A new eight-coordinated interstitial site, previously unreported for paulkerrite-group minerals, is occupied by Ca2+ cations. Weak diffuse diffraction spots in reconstructed precession images for hydroxylbenyacarite violate the a and b glide plane extinctions for Pbca and are consistent with local, unit-cell-scale regions of monoclinic, P 21/ c structure, in which ordering of the interstitial K+ and Ca2+ cations occurs. [ABSTRACT FROM AUTHOR]

Pleysteinite, [(H 2 O) 0.5 K 0.5 ] 2 Mn 2 Al 3 (PO 4) 4 F 2 (H 2 O) 10 ⚫ 4H 2 O, is the aluminium analogue of benyacarite, from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, Germany. It was found in specimens of altered zwieselite, in association with nordgauite, fluellite, rockbridgeite, pyrite and columbite. Pleysteinite occurs as isolated and small aggregates of colourless, stubby prisms that are typically 10 to 30 µ m wide and up to 100 µ m long. The crystals are flattened on {010} and bounded by {111} , {100} and {001} planes. The calculated density is 2.34 g cm -3. Optically, pleysteinite crystals are biaxial (+), with α=1.566(2) , β=1.580(2) , γ=1.600(2) (measured in white light) and 2 V (meas.) = 80(1) ∘. The empirical formula from electron microprobe analyses and structure refinement is [(H 2 O) 0.50 K 0.50 ] 2 (Mn 1.20 Mg 0.49 Fe 0.272+ Zn 0.05) ∑2.01 (Al 1.63 Fe 0.203+ Ti 0.194+) ∑2.02 (Al 0.56 Ti 0.444+) (PO 4) 4.02 [F 0.58 O 0.31 (OH) 0.11 ] 2 (H 2 O) 10 ⚫ 3.92H 2 O. Pleysteinite has orthorhombic symmetry, with space group Pbca and unit-cell parameters a = 10.4133(8) Å, b=20.5242(17) Å, c=12.2651(13) Å, V=2621.4(4) Å 3 and Z=4. The crystal structure was refined using single-crystal data to wR obs=0.054 for 1692 reflections with I>3σ(I). The crystal structure contains corner-connected linear trimers of Al-centred octahedra that share corners with PO 4 tetrahedra to form 10-member rings parallel to (010). K + cations and water molecules are located in the rings. Additional corner-sharing of the PO 4 tetrahedra with Mn(H 2 O) 4 O 2 octahedra occurs along [010] to complete the 3D framework structure. [ABSTRACT FROM AUTHOR]

Whiteite-(CaMnFe), CaMn 2+ Fe 22+ Al 2 (PO 4) 4 (OH) 2 ⋅ 8H 2 O, is a new whiteite-subgroup member of the jahnsite group from the Hagendorf-Süd pegmatite, Oberpfalz, Bavaria, Germany. It was found in vugs in an altered feldspar area of a specimen composed predominantly of rockbridgeite, with hureaulite and relic triphylite. Other associated minerals in small vugs in the specimen were strengite and laueite. Whiteite-(CaMnFe) occurs as sprays and clusters of colourless to pale yellow, rod-like crystals, with diameters of typically 10 to 50 µ m and lengths up to ∼ 500 µ m. The crystals are flattened on {001} and elongated along [010]. The measured density is 2.80(2) g cm -3. Optically, whiteite-(CaMnFe) crystals are biaxial (+), with α=1.608(3) , β=1.612(3) , γ=1.624(3) and 2 V (meas.) = 59(1) ∘. The empirical formula from electron microprobe analyses and structure refinement is (Ca 0.70 Mn 0.30)Mn(Fe 1.232+ Mn 0.49 Mg 0.29 Zn 0.06) (Al 1.88 Fe 0.123+)(PO 4) 3.96 (OH) 2 (H 2 O) 8. Whiteite-(CaMnFe) is monoclinic, P2 /a , a=14.925(5) , b=7.0100(14) , c=10.053(2) Å, β=111.31(2) ∘ , V=979.9(4) Å 3 and Z=2. The crystal structure was refined using single-crystal data to wRobs=0.052 for 1613 reflections with I>3σ(I). Site occupancy refinements confirm the ordering of dominant Ca, Mn and Fe 2+ in the X , M 1 and M 2 sites, respectively, of the general jahnsite-group formula XM 1 M 2 2 M 3 2 (H 2 O) 8 (OH) 2 (PO 4) 4. [ABSTRACT FROM AUTHOR]