Lithioforit a kryptomelan/hollandit z Kladské ve Slavkovském lese (Česká republika)

The uranium-lead mineralisation was found in the mine dump material in the locality Bezděkov (Tachov area, western Bohemia, Czech Republic). Galena occurs as coarse-grained aggregates up to 5 cm in size in quartz gangue, partly replaced by cerussite. Cerussite forms massive and powdery aggregates replacing galena. It is orthorhombic, space group Pmcn with unit-cell parameters refined from X-ray powder diffraction data: a 5.1848(2), b 8.5001(3), c 6.1478(2) Å and V 270.937(13) Å3. Kasolite forms globular aggregates covering the area up to several cm2. It is monoclinic, space group P21/c, the unit-cell parameters refined from X-ray powder diffraction data are: a 6.7133(6), b 6.9516(8), c 13.2666(14) Å, β 104.156(8)o and V 600.33(11) Å3. The chemical analyses of kasolite correspond to the empirical formula Pb1.12Fe0.03Ca0.02K0.01(UO2)1.11(SiO4)1.00·H2O on the base of Si = 1 apfu. The Bezděkov ore occurrence belongs to the shear-zone hosted uranium mineralisation. The discovered mineralization originated by the weathering of galena and uraninite in conditions of supergene zone in-situ.

A rare uranium supergene minerals, phurcalite and uranophane-beta, were found in association with metaautunite at fissures of granitoid rocks in the active Wagner quarry in Ruprechtice near Liberec (northern Bohemia, Czech Republic). Phurcalite occurs there as bright to deep yellow coatings with an area up to 10 × 3 mm in size composed of acicular to columnar crystals up to 0.5 mm in length. It is orthorhombic, space group Pbca, the unit-cell parameters refined from X-ray powder diffraction data are: a 17.3973(18), b 16.0161(15), c 13.5693(19) Å, V 3780.9(5) Å3. Chemical analyses of phurcalite correspond to the empirical formula Ca2.20(UO2)3.06(PO4)1.96(AsO4)0.04O2.26·7H2O. Uranophane-beta forms a relatively abundant pale yellow coatings of up to 2 × 2 cm in size composed of translucent to transparent acicular crystals with a vitreous lustre and a length of up to 0.2 mm. It is monoclinic, space group P21/a, the unit-cell parameters refined from X-ray powder diffraction data are: a 13.959(2), b 15.5420(16), c 6.6227(9) Å, β 91.43(1)o and V 1436.3(2) Å3. Chemical analyses of uranophane-beta correspond to the empirical formula Ca1.09(UO2)1.99[(SiO3OH)1.68 (PO4)0.29(AsO4)0.03]Σ2.00·5H2O. Metaautunite occurs there as abundant light yellow aggregates with an area up to some cm2 in size composed of tiny (up to 0.5 mm) tabular crystals or rarely as well-developed individual tabular crystals up to several mm in size. It clearly differs from other minerals in the association by very strong yellow-green luminescence in both short- and long-wave UV radiation. It is tetragonal, space group P4/nmm, the unit-cell parameters refined from X-ray powder diffraction data are: a 7.006(2), c 16.899(4) Å and V 829.4(6) (5) Å3. Chemical analyses of metaautunite correspond to the empirical formula Ca1.03(UO2)2.09(PO4)1.96(AsO4)0.04·6H2O.

Two zeolites are described from the pyrite-manganese deposit Chvaletice near Přelouč, central Bohemia, Czech Republic. Ferrierite-Mg forms brown, up to 5 mm long flat needles, radially arranged, which grow on grey-brown fine-grained rock composed of quartz, pyrite and Mn-silicates. The unit-cell parameters of ferrierite-Mg, refined from the powder X-ray diffraction data, are a = 19.162(14), b = 14.125(13), c = 7.495(6) Å and V = 2028.8(9) Å3 (space group Immm). Chemical analyses correspond to the empirical formula (Mg2.66Ca0.44Mn0.41Fe0.30Ba0.29K0.16Na0.10Sr0.03)Σ4.39(Al7.77 Si27.96O72)·18 H2O. The Ba-rich heulandite forms aggregates up to several cm in size composed of transparent gold-brown grains with characteristic pearly luster at cleavage planes. The unit-cell parameters of heulandite, refined from the powder X-ray diffraction data, are a = 17.732(2), b = 17.823(4), c = 7.4290(15) Å, β = 116.3(2) ° and V = 2104.2(6) Å3 (space group Cm). In BSE images, its aggregates are not homogenous. Ba-poor part of analyses corresponds to heulandite-Ca and heulandite-K, Ba-rich part beside Ca- and K-dominant members also to very rare heulandite-Ba. Both studied zeolites contain a significant content of Mn, ranging between 0.32 - 0.70 apfu (ferrierite-Mg) and 0.09 - 0.28 apfu (Ba-rich heulandite).

The crystal structure of a novel open-framework gallogermanate, SU-66 {|(C6H18N2)18(H2O)32|[Ga4.8Ge87.2O208]}, has been solved from laboratory X-ray powder diffraction (XPD) data by using a direct-space structure solution algorithm and local structural information obtained from infrared (IR) spectroscopy. IR studies on 18 known germanates revealed that the bands in their IR spectra were characteristic of the different composite building units (CBUs) present in the structures. By comparing the bands corresponding to Ge—O vibrations in the IR spectra of SU-66 with those of the 18 known structures with different CBUs, the CBU of SU-66 could be identified empirically as the Ge10(O,OH)27 cluster (Ge10). The unit cell and space group (extinction symbol P--a; a = 14.963, b = 31.593, c = 18.759 Å) were determined initially from the XPD pattern and then confirmed by selected-area electron diffraction. The structure of SU-66 was solved from the XPD data using parallel tempering as implemented in FOX [Favre-Nicolin & Černý (2002). J. Appl. Cryst. 35, 734–743] by assuming P21 ma symmetry and two Ge10 clusters in the asymmetric unit. Rietveld refinement of the resulting structure using synchrotron XPD data showed the framework structure to be correct and the space group to be Pmma. The framework has extra-large (26-ring) one-dimensional channels and a very low framework density of 10.1 Ge/Ga atoms per 1000 Å3. SU-66, with 55 framework atoms in the asymmetric unit, is one of the more complicated framework structures solved from XPD data. Indeed, 98% of the reflections were overlapping in the XPD pattern used for structure solution. Tests on other open-framework germanates (SU-62, SU-65, SU-74, PKU-12 and ITQ-37) for which the XPD data, unit cell, space group and IR spectra were available proved to be equally successful. In a more complex case (SU-72) the combination of FOX and powder charge flipping was required for structure solution.

Very rare hydrated molybdenum oxide, mineral zhenruite, was found in samples from the quartz - aplite vein with molybdenite at the abandoned adit 5. květen, Vrchoslav near Krupka, Krušné hory Mountains, northern Bohemia, Czech Republic. Zhenruite forms crystalline coatings on an area of up to several cm2 on quartz gangue with jordisite and molybdenite, which are composed of intergrown hemispherical aggregates up to 0.2 mm in size. These aggregates are composed of flattened needle-like crystals, radially or fan-shapedly arranged; the length of individual crystals ranges up to 0.1 mm and their cross-section is usually around 2 × 5 μm. Zhenruite crystals are translucent to transparent, colourless to very light bluish, with a vitreous lustre; the crystalline aggregates are then opaque, whitish, light or even pastel blue. Zhenruite is monoclinic, space group P21/m, the unit-cell parameters refined from X-ray powder diffraction data are: a 9.8607(10), b 3.7051(5), c 7.1122(6) Å, β 102.425(10)° and V 249.12(5) Å3. Results of semiquantitative chemical analysis (EDS) confirm the presence of Mo and O in the studied mineral. Raman spectroscopy documents the identity of studied mineral with zhenruite from type locality and presence of molecular water and Mo octahedra in the crystal structure of zhenruite. The origin of zhenruite in association with alunogen is interpreted as product of (sub)recent supergene alteration of jordisite and molybdenite in quartz gangue in environment of abandoned mine space.

An interesting mineral association of Cu arsenates was found at abandoned ore stope at the Geschieber vein - north at the Daniel level of the Svornost mine, the Jáchymov ore district, Krušné hory, Czech Republic. Tangdanite forms thin tabular crystals up to 3 mm in size and coatings and fine crystalline aggregates on the area up to some cm2. It has light green, bluish-green to emerald green color and perfect cleavage. It is monoclinic, space group C2/c, the unit-cell parameters refined from X-ray powder diffraction data are: a 54.335(12), b 5.579(2), c 10.459(2) Å, β 95.42(3)° and V 3156(2) Å3; its chemical analyses correspond to the empirical formula Ca1.99(Cu8.72Zn0.09Ni0.04Al0.04)Σ8.89[(AsO4)3.83 (PO4)0.14(SiO4)0.03]Σ4.00(SO4)0.41(OH)8.97·9H2O on the basis As+P+Si+V = 4 apfu. The results of Raman and infrared spectroscopy confirmed an absence of carbonate group in studied tangdanite. K-rich lavendulan was found as a relatively abundant sky blue crusts and coatings on the area up to some cm2 and hemispherical aggregates with a radial structure or rarely as a group of thin tabular crystals up to 0.2 mm in size. It is monoclinic, space group P21/n, the unit-cell parameters refined from X-ray powder diffraction data are: a 10.081(12), b 19.469(12), c 10.033(9) Å, β 90.32° and V 1969(2) Å3; its chemical analyses correspond to the empirical formula (Na0.63K0.16)Σ0.79Ca1.12(Cu4.82Al0.01)Σ4.83[(AsO4)3.86(PO4)0.07 (SO4)0.06(SiO4)0.01]Σ4.00Cl0.96·5H2O on the basis As+P+V+Si+S = 4 apfu. Olivenite occurs as olive green spherical aggregates with radial structure up to 8 mm in size and rarely as groups of acicular crystals in association with strashimirite and köttigite. It is orthorhombic, space group Pnnm, the unit-cell parameters refined from X-ray powder diffraction data are: a 8.6204(10), b 8.2332(9), c 5.9337(11) Å and V 421.13(7) Å3; its chemical analyses correspond to the empirical formula (Cu1.94Ni0.01Al0.01)Σ1.96[(AsO4)0.97(VO4)0.02(PO4)0.01]Σ1.00(OH)0.93 on the basis As+V+P = 1 apfu. Strashimirite forms there light green crystalline coatings on the area up to several cm2 and spherical aggregates with a radial structure in association with olivenite and lavendulan. Strashimirite is probably monoclinic, space group P2, the unit-cell parameters refined from X-ray powder diffraction data are: a 9.991(9), b 18.466(9), c 8.986(8) Å, β 96.5(2)° and V 1574(3) Å3; its chemical analyses correspond to the empirical formula (Cu7.83Ni0.18Ca0.09Zn0.06Co0.02Al0.02)Σ8.20 [(AsO4)3.81(PO4)0.07 (SO4)0.07(VO4)0.03(SiO4)0.02]Σ4.00 (OH)4.45·5H2O on the basis As+P+Si+V+S = 4 apfu. Chalcophyllite was found as rare emerald green thin tabular crystals up to 0.5 mm in size and crystalline aggregates. Its chemical composition is possible to express on the basis As+S+P+Si = 7 apfu by the empirical formula Cu17.83Al1.97[(AsO4)4.00(PO4)0.09]Σ4.09[(SO4)2.80(SiO4)0.11]Σ2.91 (OH)23.27·36H2O. Brochantite, devilline, köttigite, erythrite and gypsum were also found in the association with Cu arsenates. The origin of the described mineral association is connected with (sub)recent weathering of primary ore minerals (tennantite, sphalerite, nickelskutterudite) in relatively dry conditions of abandoned mine adits.

A very rare mineral lindgrenite, Cu3(MoO4)2(OH)2, was found in material from the 3rd level of abandoned Cínovec mine 1 of the Cínovec Sn-W deposit, Krušné hory Mountains, northern Bohemia. This is the first occurrence of this mineral in the Czech Republic. Lindgrenite occurs there as olive green irregular coatings on the area up to 0.5 × 1 cm in size formed by hemispherical to spherical aggregates up to 0.3 mm across with crystalline surface in association with brochantite. Lindgrenite is monoclinic, space group P21/n, the unit-cell parameters refined from X-ray powder diffraction data are: a 5.3934(18), b 14.032(2), c 5.6098(15) Å, β 98.54(2)° and V 419.86(16) Å3. Chemical analyses of lindgrenite correspond to the empirical formula (Cu2.92Fe0.03)Σ2.95(MoO4)1.97(PO4)0.07(AsO4)0.01(OH)1.70 on the basis of 5 atoms pfu. Its origin is connected with simultaneous weathering of primary Cu (tennantite) and Mo (molybdenite) minerals in the conditions of supergene zone in-situ.

A very rare mineral szmikite, Mn(SO4)·H2O, was determined at historical samples from the western part of upper level of the Chvaletice quarry (10 km W from Přelouč, eastern Bohemia, Czech Republic). This is the first occurrence of this mineral in the Czech Republic. Szmikite occurs there as soft distinctly porous crusts up to 10 cm in size formed by tiny (1 - 5 μm) transparent, imperfectly developed crystals. It is white, sometimes with a weak pink or yellow tints. Szmikite is monoclinic, space group C2/c, the unit-cell parameters refined from X-ray powder diffraction data are: a 7.063(3), b 7.6418(18), c 7.836(3) Å, β 118.14(2)o and V 372.9(4) Å3. The result of ICP OES analysis corresponds to following cation composition of studied szmikite: 0.649 apfu Mn, 0.339 apfu Mg, 0.009 apfu Fe and 0.004 apfu Ca. Vibrational (Raman and infrared) spectroscopy documents the presence of molecular water and sulphate units in the crystal structure of szmikite.

The rare Cu-Zn sulphate, ktenasite, was found in the association with schulenbergite, serpierite, gypsum and brochantite at abandoned stope of the Modrá štola adit, the ore deposit Zlaté Hory - East, Czech Republic. Ktenasite occurs there as two different (color, morphology) types, the first is olive green to dark green columnar crystals up to 4 mm in length which forms radially arranged groups or rich crystalline coatings. The second type is represented by blue to greenish blue crystalline coatings or hemispherical or fan-shaped aggregates formed by thin tabular crystals. The X-ray powder diffraction data, Raman spectra and chemical composition of both types are almost identical. Ktenasite is monoclinic, space group P21/c, the unit-cell parameters refined from X-ray powder diffraction data are: a 5.610(2), b 6.123(2), c 23.827(9) Å, β 95.27(3)o and V 815.0(4) Å3. Its chemical analyses correspond to the empirical formula Zn1.00(Cu3.13Zn0.96Mg0.07Al0.01)Σ4.17(SO4)1.98(PO4)0.01(SiO4)0.01(OH)6.32·6H2O. Schulenbergite most often occurs only as an admixture in blue-green crystalline aggregates of ktenasite, sometimes together with serpierite. More rarely, its blue tabular crystals with a pearly luster up to 0.4 mm in size were also observed. Schulenbergite is trigonal, space group R-3, the unit-cell parameters refined from X-ray powder diffraction data are: a 8.187(3), c 7.012(4) Å and V 410.5(3) Å3. Its chemical analyses correspond to the empirical formula (Cu4.96Zn2.34)7.30(SO4)1.92(SiO4)0.05(PO4)0.02 (OH)10.47·6H2O. Serpierite is relatively abundant in the studied mineral association, usually forms light blue fine crystalline coatings, its fan-shaped aggregates up to 4 mm in size formed by elongated tabular crystals have also been found more rarely. Its chemical analyses correspond to the empirical formula (Ca1.14Mn0.03Mg0.02)Σ1.19(Cu3.08Zn0.73)Σ3.81(SO4)1.99 (PO4)0.02(OH)5.97·3H2O. Abundant brochantite forms bright green crystalline coatings and tiny dark green to black-green crystals. Its chemical analyses correspond to the empirical formula (Cu3.80Zn0.17Al0.02)Σ3.99(SO4)0.99(PO4)0.01(OH)6.00. The origin of studied mineral association is connected with sub-recent weathering of primary sulphides (pyrite, pyrrhotite, sphalerite and chalcopyrite) in the conditions of abandoned mine space.

An interesting mineral association of paratacamite, nantokite, cuprite and an unnamed NaCuCl-arsenate was found at sample from the Jáchymov ore district (probably 12th level of the Geschieber vein, Svornost mine), Krušné hory Mountains, Czech Republic. Paratacamite occurs as light greenish-blue to whitish green irregular aggregates up to 2 mm in size. It is trigonal, space group R-3, the unit-cell parameters refined from X-ray powder diffraction data are: a 13.656(8), c 14.042(11) Å and V 2268(2) Å3; its chemical analyses correspond to the empirical formula Cu3.00(Cu0.56 Ni0.38Co0.03Ca0.03)Σ1.00Cl1.91(OH)6.09 on the basis of 4 cations apfu. Nantokite forms aggregates up to 200 μm in size replacing earlier native copper. It is cubic, space group F-43m, the unit-cell parameter refined from X-ray powder diffraction data are: a 5.4164(12) Å and V 158.90(11) Å3; its chemical analyses correspond to the empirical formula Cu1.00Cl1.00 on the base of 2 apfu. Cuprite was identified only by X-ray powder diffraction data, it is cubic, space group Pn3m with unit-cell parameter a 4.2736(4) Å and V 78.08(2) Å3. An unnamed NaCuCl-arsenate occurs as lavendulane-like blue crusts with an area of up to 5 × 8 mm on altered rock or earlier paratacamite. The crusts are composed of hemispherical aggregates up to 0.2 mm in size with a very finely crystalline surface. Its X-ray powder diffraction pattern (d(Å)/Iobs: 12.808/100, 4.944/25, 3.114/16, 2.738/17, 2.516/20) does not correspond to any approved mineral species. The chemical composition of NaCuCl-arsenate is close to ideal formula NaCu5(AsO4)2(AsO3OH)2Cl·3H2O and its empirical formula based on As+P+Si+S = 4 apfu is Na1.07Ca0.24(Cu4.70Ni0.27Co0.02Zn0.01Mn0.01)Σ5.01 (AsO4)2.00[(AsO3OH)1.73(AsO4)0.13(SiO4)0.08(SO4)0.04(PO4)0.02]Σ2.00Cl1.26·3H2O. The origin of the described mineral association is connected with (sub)recent weathering of native copper in quartz veinlets in altered granite rocks.

Within the research of secondary phosphates of the Bohemian Massif, an interesting phosphate mineralization was found on a historical sample from the Veselá hora pegmatite deposit near Domažlice (Czech Republic). Jahnsite-(CaMnFe), jahnsite-(MnMnFe), frondelite, messelite-fairfieldite, mitridatite, Mn-rich fluorapatite and parafiniukite were detected in a sample collected in the year 1944, at the time of feldspar mining in the Veselá Hora deposit. Older jahnsite forms flat elongated yellow-orange crystals, up to 2 mm in size in cavities of the phosphate matrix; its chemical composition ranges from jahnsite-(CaMnFe) to jahnsite-(MnMnFe). Younger jahnsite-(CaMnFe) was observed in flat crystals with vitreous lustre and light brown-orange to pink-orange colour. The structural data for both generations are very similar. The mineral is monoclinic, space group P2/a, the unit-cell parameters refined from X-ray powder diffraction data are: a 15.009(3), b 7.1515(16), c 9.873(3) Å, β 111.1(5)° and V 988.4(3) Å3. Frondelite occurring in the cavity forms very dark green to black hemispherical aggregates, up to 1 mm in size, composed of radially arranged fibres. Frondelite is orthorhombic, space group Bbmm, the unit-cell parameters refined from X-ray powder diffraction data are: a 13.828(5), b 16.960(6), c 5.175(2) Å and V 1214.7(5) Å3. Members of the messelite-fairfieldite solid solution were observed as yellowish grains and aggregates associated with mitridatite, Mn-rich fluorapatite, parafiniukite, jahnsite-(CaMnFe) and quartz. It is triclinic, space group P-1, the unit-cell parameters refined from X-ray powder diffraction data are: a 5.476(4), b 5.763(3), c 6.566(2) Å, α 90.19(4)°, β 102.58(5)°, γ 108.45(4)° and V 988.4(3) Å3. The results of the WDS analyses and empirical formulas of all described phosphates are given in the paper.

First structural determination of layered and pillared organic derivatives of γ-zirconium phosphate by X-ray powder diffraction data

A zeolite mineralization (stellerite, chabazite-K, heulandite-Ca, lévyne-Ca and erionite-Ca) in tiny cavities of Cenozoic basaltic rocks was sampled at the Malý Jelení vrch hill (500 m above sea level) near Stráž pod Ralskem, northern Bohemia (Czech Republic) and studied by means of electron microprobe and X-ray powder diffraction. Stellerite is the most interesting zeolite in association, this find is its second confirmed occurrence in the Czech Republic. Stellerite forms colourless to white prismatic crystals up to 3 mm in size and rare fan-shaped aggregates up to 1 cm in size. It is orthorhombic, space group Fmmm, the unit-cell parameters refined from X-ray powder diffraction data are: a 13.614(2), b 18.226(2), c 17.862(2) Å and V 4432.1(9) Å3. Its chemical analyses correspond to the empirical formula (Ca4.23K0.53)Σ4.76(Si27.64Al8.11)O72·28 H2O on basis of 72 atoms of oxygen. The time sequence of crystallization of described mineralization at the Malý Jelení vrch hill is as follows: heulandite-Ca - stellerite - chabazite-K - lévyne-Ca - erionite-Ca - calcite.

In materials and earth science, but also in chemistry, pharmaceutics and engineering, the quantification of elements and crystal phases in solid samples is often essential for a full characterization of materials. The most frequently used techniques for this purpose are X-ray fluorescence (XRF) for elemental analysis and X-ray powder diffraction (XRPD) for phase analysis. In both methods, relations between signal and quantity do exist but they are expressed in terms of complex equations including many parameters related to both sample and instruments, and the dependence on the active element or phase amounts to be determined is convoluted among those parameters. Often real-life samples hold relations not suitable for a direct quantification and, therefore, estimations based only on the values of the relative intensities are affected by large errors. Preferred orientation (PO) and microabsorption (MA) in XRPD cannot usually be avoided, and traditional corrections in Rietveld refinement, such as the Brindley MA correction, are not able, in general, to restore the correct phase quantification. In this work, a multivariate approach, where principal component analysis is exploited alone or combined with regression methods, is used on XRPD profiles collected on ad hoc designed mixtures to face and overcome the typical problems of traditional approaches. Moreover, the partial or no known crystal structure (PONKCS) method was tested on XRPD data, as an example of a hybrid approach between Rietveld and multivariate approaches, to correct for the MA effect. Particular attention is given to the comparison and selection of both method and pre-process, the two key steps for good performance when applying multivariate methods to obtain reliable quantitative estimations from XRPD data, especially when MA and PO are present. A similar approach was tested on XRF data to deal with matrix effects and compared with the more classical fundamental-parameter approach. Finally, useful indications to overcome the difficulties of the general user in managing the parameters for a successful application of multivariate approaches for XRPD and XRF data analysis are given.

At the Ag-Pb-Zn deposit Hříva near Louňovice pod Blaníkem (Central Bohemian Region, Czech Republic), supergene mineralization with relatively abundant samples of coronadite, pyromorphite and hinsdalite was newly detected. Coronadite forms black to several mm thick crusts on quartz vein or hinsdalite crusts. Coronadite is monoclinic, space group I2/m, the unit-cell parameters refined from X-ray powder diffraction data are: a 9.946, b 2.866(2), c 9.839 Å, β 90.34(2)° and V 280.4(4) Å3. Chemical analyses of coronadite correspond to the empirical formula (Pb1.32Na0.05Co0.03Ba0.02K0.01Ca0.01Mg0.01)Σ1.45Mn4+5.25(Mn3+1.95Al0.38Cu0.30 Fe0.08Si0.02Zn0.01P0.01)Σ2.74 (O15.82F0.17mCl0.01)Σ16 calculated on the basis (Mn+Fe+Al+Cu+Zn+Si+P) = 8 apfu. Pyromorphite occurs there as white to creamy crusts up to 2 mm thick. Its empirical formula calculated on the basis P+As = 3 apfu is Ca0.04Pb5.04[(PO4)2.98(AsO4)0.02]Σ3.00Cl1.14. Most interesting is relatively rare hinsdalite, which forms light green to blue-green crystalline crusts up to 0.1 mm thick on quartz or pyromorphite. Hinsdalite is trigonal, space group R-3m, the unit-cell parameters refined from X-ray powder diffraction data are: a 7.002(6), c 16.807(7) Å and V 713.6(7) Å3. Chemical analyses of hinsdalite correspond to the empirical formula Pb1.06Al2.73Cu0.11 [(PO4)1.18(SO4)0.82]Σ2.00(OH)6.36 on the basis P+S+As = 2 apfu.