Peter Bacik

Comenius University Bratislava · Department of Mineralogy Petrology and Economic Geology

A complex crystal-chemical investigation based on spectroscopic methods, Electron MicroProbe Analysis (EMPA), and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was made on sphalerite samples from the Terézia and Rozália veins in the Banská Štiavnica ore district. The yellow (sample A) and olive-green sphalerite (C) are in...

The conversion of waste/by-product materials into efficient sorbents is at the forefront of innovative remediation techniques. In the present study, the relationships among the synthesis conditions, physicochemical properties of synthesized sorbents and Zn²⁺ and Ni²⁺ removal efficiencies were studied in detail. Zeolite X, zeolite P, phillipsite, an...

The beryllium silicate minerals phenakite and bertrandite have been identified in granitic pegmatite dykes of beryl-columbite subtype of Variscan age (~340-355 Ma), associated with S- to I-type granitic rocks of the Tatric Superunit, Western Carpathians (Slovakia). These two beryllium silicates and associated minerals were characterized by elect...

EPMA conditions used for each element. Mnz = monazite; Xtm = xenotime; Ap = apatite; Aln-Czo = allanite-clinozoisite; Hld-Hin = hellandite-hingganite; n.a. = not analysed Note: Wrong DOI https://doi.org/10.1017/S0007123422000011

Two contrasting reaction coronae were developed around rare earth element (REE) accessory phosphates in Variscan metagranitic rocks, which have been overprinted by Alpine blastomylonitisation from the Fabova Hol’a Massif, in the Veporic Unit, Western Carpathians, Central Slovakia. The Th–U–Pb total EPMA age determination of primary magmatic monazit...

A hydrothermal quartz vein with REE-U-Au mineralization in the Zimná Voda (Gemeric Unit, Western Carpathians, Slovakia) is associated with contact metamorphism between Permian granites and host phyllites and metaquartzites. It contains unique REE minerals from the monazite and xenotime groups. Monazite-(Ce), monazite-(Nd), monazite-(Sm), and Gd-dom...

A heat treatment was performed on selected epidote and clinozoisite crystals to establish the nature of any changes in the optical and crystal-chemical properties and to identify a breakdown product using a wide spectrum of analytical methods. Natural samples were heated from 900 to 1200 °C under atmospheric pressure in ambient oxidation conditions...

The study reveals the relationships between crystal-chemical and genetic properties of beryl from several rare-element granitic pegmatites of the LCT family from the Damara Belt, Namibia. Based on their chemical compositions, the studied beryl samples can be divided into two groups. Beryl from the first group (the Engelbrecht's and Etusis pegmatite...

Microlite-group minerals occur as common replacement products after primary and secondary columbite-group minerals (CGM) in albitised blocky K-feldspar and in coarse-grained, muscovite-rich units of the Schinderhübel I, Scheibengraben and Bienergraben beryl–columbite pegmatites in the Maršíkov District (Silesian Unit, Bohemian Massif, Czech Republi...

We studied 12 crystal fragments of natural spinel from Mogok, Myanmar and Lục Yên, Vietnam. All samples were crystal fragments of various shapes and sizes and several of them had gemological quality. Studied samples are enriched in Cr, V, Fe2+, Fe3+, Zn, which are responsible for its resulting color. They could be divided into groups of V-Cr spinel...

Metamorphic evolution of an accretionary wedge can be constrained by a reconstructed P-T conditions of the oceanic and continental margin fragments. This paper deals with the metamorphic overprinting of the Inner Western Carpathians (IWC) Meliatic Triassic-Jurassic paleotectonic units after the closure of the Neotethyan Meliata Basin. Medium to hig...

Theoretical bond-length calculations from ideal bond valences for each ion and coordination allows for the prediction of ion site preference and partitioning in tourmaline structures at low-pressure conditions. A comparison of calculated data with published bond-length values enables the determination of the range of structurally stable bond length...

In talc-magnesite veins in serpentinite near Muránska Dlhá Lúka (MDL), Slovakia, yellow euhedral to subhedral crystals apatite of a gem quality occur. It has a composition of hydroxylapatite with F − varying between 0.29 and 0.34 apfu, Cl − in range of 0.02-0.05 apfu and calculated OH − content between 0.62-0.68 apfu. Moreover, [CO 3 ] 2− molecules...

The identified mineral association in the crystalline limestones from the manganese locality Čučma - Čierna baňa consists of garnets and pyroxenes. Mineralogical composition of the samples Ču-1 and Ču-2 is represented by zonal garnets with Grs76.12-82.31; Adr17.69-23.88 composition in the core and Grs95.48-97.05; Adr2.95-4.52 composition in the rim...

Copper- and Mn-bearing elbaitic tourmaline (“Paraíba tourmaline”) sometimes contains significant amounts of Pb and Bi. Their position in the tourmaline crystal structure was studied with correlation analysis and bond valence calculations. Correlations between the F content and the X-site charge allow predicting the X-site occupancy. Three sets of t...

Different structure and symmetry of spinel and chrysoberyl influence their luminescence spectra Observed with Raman spectroscopy. Luminescence bands of spinel at 677, 685, 697, 710 a 718 nm were assigned to Cr3+. Luminescence duplet located at 685 and 687 nm belongs to R1 and R2–lines for the Cr3+ ion, the electron transition 2Eg → 4A2g, N1 and N4...

An assemblage of alunite-supergroup minerals (ASM), rhabdophane-group minerals (RGM), goethite and associated clay minerals occurs in Permian A-type microgranite in the eastern part of the Velence Hills, Hungary. The secondary sulfates/phosphates include jarosite, Pb-rich jarosite and alunite, corkite, hinsdalite and rhabdophane-(Ce), -(La) and -(N...

A unique assemblage of hedyphane-group minerals of the apatite supergroup associated with galena, cerussite, and calcite occurs in a Permian aplite dike crosscutting orthogneisses belonging to the pre-Alpine basement of the Veĺký Zelený Potok Valley in the Veporic Unit, Western Carpathians, Central Slovakia. The secondary Ca-Pb phosphates include p...

The period of the Cretaceous marked a time of convergence in the Tethyan realm, characterized by both collisions and local ophiolitic obduction. Sedimentary records from this period are full of detritic materials of unknown provenance, so-called exotics. Among these exotic rocks and minerals was tourmaline with complex zonation which began to appea...

Mineral composition of marbles, basalt metapyroclastics and chlorite schists was determined at the locality of Markuška. Magnesium-rich actinolite to tremolite was found in basalt metapyroclastics and marbles. In amphiboles, the Fe content ranges from 0.71 to 0.95 apfu in the iron-rich zone and from 0.40 to 0.63 apfu in the Mg-rich zone. At the A s...

The site preference for each cation and site in beryl based on bond-length calculations was determined and compared with analytical data. Tetrahedral SiO4 six-membered rings normally have no substitutions which results from very compact Si4+–O bonds in tetrahedra. Any substitution except Be would require significant tetrahedral ring distortion. The...

Background: A significant proportion of anthropogenic dust particles are present in the atmosphere. In particular, these include industrial and municipal dust, black carbon from fossil fuels and biomass. Mineralogical research of dust particles in the air is important for knowing their impact on public health in hazardous work environments (not on...

The recrystallized limestones from Magnet Hill near Tisovec (Slovak Republic) locally contain breccia fragments with veins containing garnets and vesuvianite. Garnets have an oscillatory zoning with dominant grossular component in the range of 70 - 75 mol. % and 88 - 95 mol. % in Fe- and Al-rich zones, respectively. Andradite component varies betwe...

Illitic clay from the locality of Liepa, Latvia, was investigated using dynamic thermomechanical analysis during the heating and cooling stages of firing. Differential thermal analysis, thermogravimetry, thermodilatometry, X-ray diffraction and porosimetry were also performed to shed light on the processes influencing the elastic properties of clay...

We studied three samples from the following localities: Madagascar (RMA-1) and Mysore, India (RMI-1 and RMI-2). The RMA-1 and RMI-1 samples have the most intensive band at the 690 and 698 nm. The RMI-2 sample has a broader luminescence band with two intense bands at 690 and 699 nm. In the region of about 692 nm (2 T1g→ 4 A2g), and 694 nm (2 Eg→ 4 A...

Journal of Gemmology Vol. 36 No. 5 pp. 409-410

Minerals of the rhabdophane group and the alunite supergroup in microgranite: products of low-temperature alteration in a highly acidic environment from the Velence Hills, Hungary – ERRATUM - Martin Ondrejka, Peter Bačík, Tomáš Sobocký, Pavel Uher, Radek Škoda, Tomáš Mikuš, Jarmila Luptáková, Patrik Konečný

An error was introduced in the final editing stages of production of this paper in Mineralogical Magazine, 82(6), 1277–1300 under the headings Discussion, subheading: ASM and RGM compositional variations, p 1296; the word “should” was replaced mistakenly by “shouldn’t” The correct text is: “All these data together with Fe-rich RGM from the Velence...

Andradite, variety demantoid, is a rare gem mineral. We describe gem-quality garnet crystals from serpentinized harzburgites from Dobšiná, Slovakia which were faceted. Both the andradite samples were transparent, with a vitreous luster and a vivid green color. They were isotropic with refractive indices >1.81. The measured density ranged from 3.82...

Crystal-chemical properties, and octahedral substitution role in particular, of beryl from weakly fractionated intragranitic pegmatite at Predné Solisko, Vysoké Tatry Mts. (Slovakia) is described in detail. The studied beryl was found in granitic pegmatite derived from biotite I-type granodiorite. It has a weakly zoned core with variable Fe and Mg...

Alkaline schorlitic tourmaline with domains of myrmekitic quartz and tourmaline intergrowths is reported for the first time from quartzo-feldspathic gneisses of the Tso Morari Crystalline Complex (TMCC), Eastern Ladakh Himalaya. Except of schorlitic tourmaline unbroken, brown-green dravitic tourmaline occurs in melanocratic layers of the gneiss. Th...

Fourteen gem-quality green-coloured beryl samples of different origin were investigated by standard gemmological methods and Raman, X-ray fluorescence and optical absorption spectroscopy. All investigated 14 samples were identified as beryl by Raman spectroscopy. Five main transition elements were detected (Cr, V, Fe, Cu, Ni). Six samples were sign...

An assemblage of alunite-supergroup minerals (ASM), rhabdophane-group minerals (RGM), goethite and associated clay minerals occur in Permian A-type porphyritic microgranite in the eastern part of the Velence Hills, Hungary. The secondary sulfates/phosphates include jarosite, plumbian jarosite and alunite, corkite, hinsdalite, rhabdophane-(Ce), -(La...

Calc-alkaline lamprophyres are known from several localities in the Malá Fatra Mountains. They form dykes (0.5-3 m) of varying degree of alteration that have intruded the surrounding granitoid rocks which are often incorporated xenoliths. Clinopyroxenes (diopside to augite), amphiboles (kaersutitic), biotites (annite) and plagioclases are major pri...

The structure of tourmaline-supergroup minerals includes two types of octahedral sites: the ZO6 octahedron is smaller and more distorted than the YO6 octahedron. The octahedral sites metrics were studied and their dependency on the chemical composition unconstrained by Y,Z-site disorder assignment. Published chemical and structural data were collec...

Stilpnomelane was recently identified at the Trohanka locality near Prakovce, Slovakia. It forms nests up to several cm in size or veinlets up to 2 cm thick, which consist of reddish-brown to golden-brown platy aggregates in coarsegrained amphibole (predominantly ferro-hornblende). Microscopic aggregates of epidote were also observed in association...

Granitic pegmatites are relatively common rocks in pre-Alpine (Paleozoic) crystalline basement of the Tatric and Veporic Units of the Western Carpathians. They are genetically connected with orogen-related Variscan granitic rocks of S-or I-type affinity. The most evolved West-Carpathian pegmatites contain beryl and/or Nb-Ta oxide minerals (columbit...

Spinel (MgAl2O4) contains various concentrations of Cr3+ ions in the octahedral coordination. Spinel belongs to the cubic space group Oh7 with eight formula units per cell and two sites for metal ions. The A site (Mg) has the tetrahedral coordination with Td symmetry and the B site (Al, Cr) is six-fold distorted with octahedral coordination in D3d...

Four beryl samples from various Namibian localities Etusis (ETU), Kudoberg (KUD), Baobismond (BAO) – Karibib and Engle Brecht (EN) – Strathmore) were investigated by wide spectrum of analytical methods. The studied beryls are derived from complex-type petalite-subtype pegmatites of LCT family. BAO and KUD samples are assigned to normal beryls (0.99...

Tourmaline is an important gangue mineral in a large number of Cretaceous siderite-quartz-sulphide hydrothermal veins in the Gemeric Unit, Slovak Ore Mountains, Slovakia, such as Dobšiná, Vlachovo, Rožňavské Bystré, Hnilčík, Rakovnica, Novoveská Huta, Gretla, Rudňany, and Bindt. In this study we combine by electron microprobe analysis, powder X-ray...

Laser has dual role in mineralogy; minerals are used as a source of laser radiation and laser is employed in mineral analytical study. Therefore, we used spectroscopic methods to study Cr-bearing minerals, which are potential laser sources. Chemical composition was determined by XRF analysis, and shows that ruby is enriched in Fe, Ti and Cr, alexan...

209 Úvod Článok prináša nové informácie o minerálnom zložení mramorov, ktoré môžu byť perspektívne použité pre do-plnenie poznatkov geodynamického vývoja klátovského komplexu gemerika. Skúmané mramory neboli doteraz v takomto rozsahu podrobne študované a publikačne spra-cované. Geologická charakteristika Koncepcia geologického vývoja klátovského ko...

The newly defined gadolinite supergroup approved by the IMA CNMNC (vote 16-A) includes mineral species that have the general chemical formula A2MQ2T2O8’2 and belong to silicates, phosphates and arsenates. Each site is occupied by: A Ca, REE (Y and lanthanoids), actinoids, Pb, Mn2þ, Bi; M Fe, □ (vacancy), Mg, Mn, Zn, Cu, Al; Q B, Be, Li; T Si, P, As...

In ceramic materials, depolarization effects take place when an external electrical field is removed. Therefore, an understanding of mechanisms of polarization and depolarization is important for a more accurate control of furnace temperature and DC or pulse electrical field in flash sintering. In this paper, depolarization currents were measured i...

Tourmaline-supergroup minerals are common gangue minerals in Sb-hydrothermal veins on Betliar – Straková, Čučma – Gabriela and Rožňava – Peter-Pavol vein deposits in the Rožňava area, Slovakia. Tourmaline-supergroup minerals form relatively large prismatic to radial aggregates of parallel black to greyish-black crystals. Tourmaline-supergroup miner...

Borate minerals of the ludwigite group (LGM) and szaibélyite in association with hydroxylclinohumite, clinochlore, a serpentine mineral, magnesian magnetite, spinel, magnesite, dolomite and sulphide minerals, occur in a magnesian exoskarn in the R-20 borehole located in the Vysoká – Zlatno Cu-Au porphyry-skarn deposit, located within the Štiavnica...

Red beryl from Utah is chemically homogeneous and contains only Fe < 0.163, Mn < 0.018, and Mg < 0.016 apfu. Channel sites contain only up to Cs 0.011, K 0.009, Rb 0.004, and Na 0.004 apfu. This suggests only very slight tetrahedral (Cs,K,Rb)Li□-1Be-1 substitution, octahedral Na(Fe²⁺,Mg)□-1Al-1 substitution can be excluded. Fe and Mn are trivalent...

Raw illitic clay (80 % illite, 4 % montmorillonite, 4 % orthoclase, and 12 % quartz) was milled in a planetary ball mill for 0, 60, 120, and 180 min in air. From milled clay, samples for XRD, granulometry, thermogravimetry, DTA, and dilatometry measurements were prepared. It was found that 1) the phase composition is almost unchanged by milling; 2)...

The chemical zonality of amphiboles in contact zone of marbles and metabasites in the locality Trohanka near Prakovce (Slovakia) was identified. Observed locality belongs to the Gelnica Group of Early Paleozoic of Gemericum (Late Silurian - Devonian). The zonality reflects chemical composition of core and rim parts of amphibole crystals. In the sam...

Gadolinite supergroup was newly defined and approved by the CNMNC IMA. It consists of mineral species having the monoclinic P2 1 /c crystal structure with the general chemical formula A 2 MQ 2 T 2 O 8 ϕ 2. Each site is occupied as follows: A-Ca, REE (Y and lanthanoids), actinoids, Pb, Mn 2+ , Bi; M-Fe, □ (vacancy), Mg, Mn, Zn, Cu, Al; Q-B, Be, Li;...