This report deals with a general reexamination of the systematics of sulfosalts. It represents an update of the activity of the Sulfosalt Sub-Committee within the Commission on Ore Mineralogy of the International Mineralogical Association, in connection with the Commission on New Minerals, Nomenclature and Classification (CNMNC-IMA). Part I presents generali- ties of sulfosalt definition and nomenclature. After an extended chemical definition of sulfosalts, attention is focused on "classic" sulfosalts with As 3+ ,S b 3+ ,B i 3+ or Te 4+ as cations, corresponding to the general formula (Me + , Me' 2+ , etc.)x ((Bi, Sb, As) 3+ , Te 4+ )y ((S, Se, Te) 2− )z (Me, Me': various metals). General aspects of their chemistry and classification principles are summarized, especially with regard to chemical substitutions and modular analysis of complex crystal structures. On this basis, Part II presents a review of sulfosalt systematics. Six main crystal-chemical sub-groups are distinguished (plus some unclassified species), con- cerning more than 220 valid mineral species. Among others whose status is questioned are those considered to be varieties of well-defined species; minerals with ill-defined X-ray data; those that are possibly identical species; and those that represent the potential revalidation of old species. More than 50 crystal structures still remain unsolved, among which about a half probably corresponds to new structure types.

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Sulfosalt systematics: a review. Report of the sulfosalt sub-committee of the IMA Commission on Ore Mineralogy

Focussed ion beam–transmission electron microscopy applications in ore mineralogy: Bridging micro- and nanoscale observations

The labyrinthine world of arsenic minerals has piqued the curiosity of many researchers in mineralogy, geochemistry, chemistry, and environmental sciences. Arsenic was known to the ancient civilizations; there are written Greek, Roman, and Chinese reports about minerals and substances of this element (Emsley 2001). The discovery of elemental arsenic is attributed to Albertus Magnus (1193–1280) who prepared it by reduction of As2O3. The common public association of arsenic and poison is the heritage of a long history of eliminating unwanted and unloved ones with compounds of this element. Mary Ann Cotton (1832–1873) was charged with murder of her mother, three husbands, a lover, eight of her own children, and seven stepchildren, all of them with an arsenic-based de-worming compound (Emsley 2005). Kořinek (1675) gave a vivid and frightening account on how a natural ferric sulfo-arsenate (bukovskýite) was used to poison the German armies of Albrecht Habsburg who invaded Bohemia in 1304. An arsenic derivative called lewisite (2-chlorovinyl-dichloroarsine) was used in the World War I (Emsley 2001). On the other hand, brightly-colored arsenic compounds were used in all imaginable products well into the 20th century. Arsenic whetted the appetite of many children as green arsenical chemicals were used as cake decorations and coatings of sugar sweets (Emsley 2005). The death of Napoleon Bonaparte has been regarded for a long time as a consequence of ingested or inhaled arsenical compouds (e.g., Aldersey-Williams 2011), however there are alternative interpretations (Lugli et al. 2011). Accidental mass arsenic poisoning occurred in Manchester in 1900 when many men drank beer contaminated with arsenic. The arsenic was tracked back to pyrite which was used to produce sulfuric acid which was employed in the manufacture of glucose for this batch of beer (Emsley 2005). Despite its toxicity, arsenic finds a few uses in …

Parageneses and Crystal Chemistry of Arsenic Minerals

Structure-property survey and computer-assisted screening of mid-infrared nonlinear optical chalcohalides

The 2008 edition represents the tenth installment of this work, which has been a standard since it was first issued by Michael Fleischer in 1971. As well, it incorporates a number of changes from the previous edition. In a number of respects, this version represents a transition from previous

Fleischer’s Glossary of Mineral Species 2008 (tenth edition).: Malcolm E. Back and Joseph A. Mandarino. Mineralogical Record Inc., P.O. Box 35565, Tucson, Arizona 85740, U.S.A., 346 pages. US$26 (soft cover). (No ISBN number).

The effect of temper on the thermal conductivity of traditional ceramics: Nature, percentage and granulometry

The crystal structure of the type specimen of vurroite from Vulcano (Aeolian Islands, Italy) has been solved and refined using single-crystal X-ray diffraction data collected at the Elettra synchrotron facility (Basovizza, Trieste). Vurroite has an OD (order-disorder) structure belonging to the category III of OD structures composed of equivalent layers. The OD-groupoid family (λ and σ partial operations) and MDO structures were derived by means of the application of the OD theory. The two theoretically possible polytypes with maximum degree of order (MDO polytypes) have pseudo-orthorhombic metric, with lattice parameters a ≈ 45.6, b ≈ 8.4, c ≈ 54 A, and a ≈ 22.8, b ≈ 8.4, c ≈ 54 A, and space group symmetries F 2 /d 11 and A 2 /d 11 , respectively. Only the former polytype (MDO 1 ) could be identified in the analyzed crystals. The MDO 1 structure was solved and refined to R = 6.26% for 4968 reflections with F o > 4σ ( F o ). In the standard C 2 /c setting of the space group the unit-cell parameters of MDO 1 are a = 8.371(2), b = 45.502(9), c = 27.273(6) A, β = 98.83(3)°, V = 10265(4) A 3 , Z = 4. Frequent twinning with (001) as the twin plane, together with the occurrence of disordered domains in the structure, was observed. The crystal structure of vurroite contains lozenge-shaped composite rods made of coordination polyhedra of Pb and Sn, interconnected into layers parallel to (010) of the standard monoclinic setting. These layers are separated by ribbons of As and Bi, each in distorted octahedral coordination. The ribbons form wavy, discontinuous double layers of PbS archetype. Lone electron pairs of As and Bi are accommodated in the central portions of the PbS-like layers. The structure of vurroite contains building blocks topologically similar to those found in the zinckenite group and in the structure of kirkiite. It can be considered a box-work structure containing the smallest possible pseudo-hexagonal block in the form of a sole octahedron.

The crystal structure of vurroite, Pb20Sn2(Bi,As)22S54Cl6 : OD-character, polytypism, twinning, and modular description

We report the first Italian occurrence of yukonite, a rare hydrated arsenate of calcium and ferric iron, from Grotta della Monaca cave, S. Agata di Esaro, Cosenza, Italy. We have studied samples of cotype yukonite from the Daulton mine, Yukon, Canada, for comparison. At Grotta della Monaca, yukonite occurs in compact masses, dark reddish brown to brownish yellow in color. At the TEM scale, it consists of a chaotic assemblage of small grains (maximum dimension 1.76 Fe 2+ 0.09 Fe 3+ 3.12 [(As 0.81 Si 0.10 P 0.09 )O 4 ] 3 (OH) 3.76 ·4H 2 O for yukonite from Grotta della Monaca and Ca 1.76 Fe 2+ 0.10 Fe 3+ 3.56 [(As 0.89 Si 0.08 P 0.03 ) O 4 ] 3 (OH) 5.16 ·3H 2 O for yukonite from the Daulton mine, close to the stoichiometry Ca 2 Fe 3 (AsO 4 ) 3 (OH) 4 ·4H 2 O. The thermogravimetric data indicate a total H 2 O content of ~17 wt%; FTIR data show that most of this occurs as H 2 O, but some OH could be present as well. The FTIR data show, in addition, the presence of ammonium and organic matter, suggesting that poorly crystalline organic matter is trapped in the material examined. Both chemical and XRD data point to a close relation with arseniosiderite [Ca 2 Fe 3 (AsO 4 ) 3 O 2 ·3H 2 O]. Both occur as oxidation products of As-bearing sulfides and seem to be composed of basically the same type of layers; arseniosiderite represents a fully crystalline substance, whereas yukonite is a semicrystalline material with a large variation in composition due to the admixture of amorphous material.

Yukonite from the grotta della monaca cave, sant’agata di esaro, italy: characterization and comparison with cotype material from the daulton mine, yukon, canada

Tazieffite, ideally Pb20Cd2(As,Bi)22S50Cl10, is a new mineral from the high-temperature fumaroles of the Mutnovsky volcano, Kamchatka Peninsula, Russian Federation. It occurs as tiny, slender, needle-shaped crystals, up to 400 μm long and 10 μm across, generally forming fibrous aggregates. Tazieffite is closely associated with greenockite, galena, mutnovskite, kudriavite, and Cd-rich cannizzarite. Other minerals spatially associated are pyrite, anhydrite, and cristobalite. Tazieffite is silvery-gray in color, occasionally with a magenta tint when it forms aggregates of extremely fine needles. It has a black streak and metallic luster. In plane-polarized incident light, tazieffite is weakly bireflectant and weakly pleochroic from dark gray to a blue-gray. Between crossed polars, the mineral is weakly anisotropic, without characteristic rotation tints. Reflectance percentages measured in air ( R min and R max) for a single grain are 33.9, 34.1 (471.1 nm), 32.8, 33.0 (548.3 nm), 32.4, 32.6 (586.6 nm), and 30.9, 31.1 (652.3 nm), respectively. Electron microprobe analyses yield the following ranges of concentrations: Pb 41.88–44.14 (avg. 42.90), Cd 0.87–1.16 (avg. 1.03), Sn 0.31–0.69 (avg. 0.48), Bi 20.43–22.94 (avg. 21.90), As 8.64–10.73 (avg. 9.66), S 16.10–17.48 (avg. 16.58), Se 0.82–1.28 (avg. 1.04), Cl 2.39–2.77 (avg. 2.63), Br 0.09–0.15 (avg. 0.12), I 0.27–0.58 (avg. 0.42). The empirical chemical formula, calculated on the basis of 44 cations, is Pb20.06(Cd0.89Sn0.39In0.02)∑1.30(As12.49Bi10.15)∑22.64 (S50.08Se1.28)∑51.36(Cl7.18I0.32Br0.15)∑7.65. Tazieffite is closely related to the halogen-sulfosalt vurroite, Pb20Sn2Bi22S54Cl6, both from a chemical and structural point of view. It represents the (Cd,As)-dominant of vurroite, according to the coupled heterovalent substitution Sn4+ + 2S2− → Cd2+ + 2Cl−. The crystal structure of tazieffite was refined in the space group C 2/ c to R = 0.0370 for 4271 reflections with I > 2σ( I ). Unit-cell parameters are a = 8.3520(17), b = 45.5920(92), c = 27.2610(55) A, β = 98.84(3)°, with V = 10257(4) A3, and Z = 4. The structure of tazieffite consists of lozenge-shaped composite rods made of coordination polyhedra of Pb around an octahedrally coordinated (Cd,Sn,Pb) position, interconnected into layers parallel to (010). These layers are separated by ribbons of As and Bi in distorted octahedral coordination. The ribbons form wavy, discontinuous double layers of the PbS archetype. Lone electron pairs of As and Bi are accommodated in the central portions of the PbS-like layers. The possibility that small amounts of NH4+ are incorporated in the crystal structure of tazieffite is discussed. The name of this new mineral species (IMA 2008-012) honors Haroun Tazieff (Warszawa, May 11, 1914–Paris, February 6, 1998), famous Belgian/French volcanologist, who was a pioneer in the field study of volcanoes and devoted his life to the study of volcanic gases.

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Tazieffite, Pb20Cd2(As,Bi)22S50Cl10, a new chloro-sulfosalt from Mutnovsky volcano, Kamchatka Peninsula, Russian Federation

We present a transmission electron microscopy (TEM) investigation of lillianite (Pb 3 Bi 2 S 6 ) and heyrovskýite (Pb 6 Bi 2 S 9 ), from Vulcano, Aeolian Islands, Italy. The minerals investigated represent the only naturally occurring Ag- and Cu-free sulfosalts in the lillianite homologous series (LHS). Three methods (crushing, ion-milling, and ultramicrotomy) were used to prepare TEM specimens. Selected area electron diffraction (SAED) patterns and high-resolution TEM (HRTEM) images indicate well-ordered crystals with only minor stacking faults and, more rarely, nanoscale intergrowths of lillianite and heyrovskýite. The latter were sometimes found to form an incommensurate structural modulation with an angle of ~29° relative to b* in the ( hk 0) plane and a wavelength of ~75 A. This represents the first observation of such incommensurate modulations in heyrovskýite. Although considerable evidence points toward an artifact induced by the sample preparation technique (i.e., ion-milling), the possibility that the incommensurate modulation could be a primary feature of heyrovskýite itself cannot be completely ruled out. The modulation could derive from an ordering process of Pb and Bi cations over Me4 and Me5 sites within the PbS-like layer or from ordering of vacancies, naturally present or induced by Bi 2 S 3 sublimation during ion-milling.

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Daniela Pinto

Papers

The effect of temper on the thermal conductivity of traditional ceramics: Nature, percentage and granulometry

The crystal structure of vurroite, Pb20Sn2(Bi,As)22S54Cl6 : OD-character, polytypism, twinning, and modular description

Yukonite from the grotta della monaca cave, sant’agata di esaro, italy: characterization and comparison with cotype material from the daulton mine, yukon, canada

Tazieffite, Pb20Cd2(As,Bi)22S50Cl10, a new chloro-sulfosalt from Mutnovsky volcano, Kamchatka Peninsula, Russian Federation

Transmission electron microscopy investigation of Ag-free lillianite and heyrovskýite from Vulcano, Aeolian Islands, Italy