We describe the new species ognitite, NiBiTe, and a Co-rich variety of maucherite, hitherto unreported; both were discovered in the Ognit ultramafic complex of Neoproterozoic age in Eastern Sayans, Russia. The mean composition of ognitite (n = 7) is: Ni 17.05, Fe 0.07, Cu 0.14, Pd 0.14, Te 32.53, Bi 49.64, total 99.57 wt.%, corresponding to: (Ni1.11Cu0.008Fe0.005Pd0.005)Σ1.13Bi0.90Te0.97 (Σ atoms = 3 apfu). Ognitite is trigonal, space group P3m1 [R1 = 0.0276 for 81 reflections with Fo > 4σ(Fo)]. The unit-cell parameters derived from the single-crystal X-ray diffraction data are: a = 3.928(1) Å, c = 5.385(1) Å and V = 71.95(4) Å3, with Z = 1. The c:a ratio is 1.37. The powder X-ray diffraction data obtained on the same fragment used for the single-crystal study are: a = 3.9332(4) Å, c = 5.3920(6) Å and V = 72.24(1) Å3. Ognitite exhibits the brucite-type structure with edge-sharing NiTe3Bi3 octahedra forming sheets parallel to (0001). It is related to melonite, but is distinct compositionally by the extreme Bi-enrichment (melonite and its synthetic analogue contain <0.4 Bi apfu), and structurally as Bi and Te are ordered at two distinct sites, leading to the loss of the centre of symmetry in ognitite.

At more than 9 wt.% Co, or ~2 apfu Co, the core of Co-rich maucherite [(Ni,Co)11As8] in a zoned crystal, which is surrounded by Co-depleted orcelite, far surpasses the norm (≤1 and up to 3.9 wt.% Co). The unit-cell parameters of the Co-rich maucherite are: a = 6.85(2) and c = 21.83(5) Å, which are based on results of synchrotron micro-Laue diffraction.

The host rock consists of serpentine, clinochlore (Mg# 95–97) and skeletal chromite. We favour the metastable crystallisation of fluid-saturated globules of a sulfide–arsenide melt to explain the anomalous compositions of ore minerals at Ognit. These anomalies seem consistent with rapid cooling in a fluid-enriched system, possibly related to late-stage degassing of the magma, as reflected in a prominent metasomatic aureole at the contact with the enclosing gneissic rocks.

The importance of emblem glyphs to Maya studies has long been recognized. Among these are emblems that have yet to be conclusively matched to archaeological sites. The Water Scroll emblem glyph is one such example, although it appears numerous times in the Classic Maya written corpus between the sixth and the eighth centuries. These many references are found at a variety of sites across the lowlands, attesting to the importance of this ancient kingdom and the kings who carried this title. In the present paper, we review the epigraphic and archaeological evidence and propose that this may be the royal title of the kings who reigned from Altun Ha, in the east central Maya lowlands, in what is now Belize. In so doing, we also begin to reconstruct the dynastic history of the Water Scroll kings, from the vantage of both local and foreign sources.

Omariniite, ideally Cu8Fe2ZnGe2S12, represents the Ge-analogue of stannoidite and was found in bornite-chalcocite-rich ores near the La Rosario vein of the Capillitas epithermal deposit, Catamarca Province, Argentina. The mineral is associated closely with three other Ge-bearing minerals (putzite, catamarcaite, rarely zincobriartite) and bornite, chalcocite, digenite, covellite, sphalerite, tennantite, luzonite, wittichenite, thalcusite and traces of mawsonite. The width of the seams rarely exceeds 60 μm, their length can attain several 100 μm. The mineral is opaque, orange-brown in polished section, has a metallic lustre and a brownish-black streak. It is brittle, and the fracture is irregular to subconchoidal. Neither cleavage nor parting are observable in the sections. In plane-polarized light omariniite is brownish-orange and has a weak pleochroism. Internal reflections are absent. The mineral is distinctly anisotropic with rotation tints varying between brownish-orange and greenish-brown. The average result of 45 electron-microprobe analyses is Cu 42.18(34), Fe 9.37(26), Zn 5.17(43), In 0.20(6), Ge 11.62(22), S 31.80(20), total 100.34(46) wt.%. The empirical formula, based on Σ(Me + S) = 25, is Cu8.04(Fe2.03In0.02)Σ2.05Zn0.96 Ge1.94S12.01, ideally Cu8+Fe2+Zn2+Ge24+S122-. Omariniite is orthorhombic, space group I222, with unit-cell parameters: a = 10.774(1), b = 5.3921(5), c = 16.085(2) Å, V = 934.5(2) Å3, a:b:c = 1.9981:1:2.9831, Z = 2. X-ray single-crystal studies (R1 = 0.023) revealed the structure to be a sphalerite derivative identical to that of stannoidite. Omariniite is named after Dr. Ricardo Héctor Omarini (1946–2015), Professor at the University of Salta, for his numerous contributions to the geology of Argentina.

The determination of the crystal structure of benleonardite (P3m1; R = 0.0321 for 1250 reflections and 102 parameters; refined formula Ag15.00Cu1.00Sb1.58As0.42S7.03Te3.97) obtained using data from a gem-quality, untwinned crystal recovered from the type material, revealed that benleonardite exhibits the structure observed for minerals of the pearceite-polybasite group. The structure consists of the stacking of [Ag6(Sb,As)2S6Te]2– A and [Ag9Cu(S,Te)2Te2]2+B layer modules in which (Sb, As) forms isolated SbS3 pyramids typically occurring in sulfosalts; Cu links two (S,Te) atoms with linear coordination, and Ag occupies sites with coordination geometries ranging from quasi-linear to almost triangular. The silver ions are found in the B layer module along two-dimensional diffusion paths and their electron densities are evidenced by means of a combination of a Gram-Charlier development of the atom displacement factors and a split model. In the structure, two S positions are completely replaced by Te (i.e. Te3 and Te4) and one is half occupied [S1: S0.514(9)Te0.486], whereas S2 is completely filled by sulfur. This distribution reflects the crystal-chemical environments of the different cations. On the basis of information gained from this characterization, the crystal-chemical formula of benleonardite was revised according to the structural results, yielding Ag15Cu(Sb,As)2S7Te4 (Z = 1) instead of Ag8(Sb,As)Te2S3(Z = 2) as previously reported. Thus, the mineral must be considered a member of the pearceite-polybasite group. A recalculation of the chemical data listed in the scientific literature for benleonardite according to the structural results obtained here leads to excellent agreement.

The crystal structure of the mineral uytenbogaardtite, a rare silver-gold sulfide, was solved using intensity data collected for a crystal from the type locality, the Comstock lode, Storey County, Nevada (USA). The study revealed that the structure is trigonal, space group R3̄c, with cell parameters a = 13.6952(5), c = 17.0912(8) Å and V = 2776.1(2) Å3. The refinement of an anisotropic model led to an R index of 0.0140 for 1099 independent reflections. The structure consists of a sub-lattice of sulfur atoms forming a distorted body-centred cubic arrangement. The structure contains distinct tri-atomic linear groups (S–Au–S) and Ag atoms bonded to four S atoms (from four different linear groups) in a distorted tetrahedral arrangement. On the basis of information gained from this characterization, uytenbogaardtite is here definitively proved to be structurally different from petzite, Ag3AuTe2 and fischesserite, Ag3AuSe2. By use of high-quality single-crystal diffraction data, the symmetry of the mineral was found to be trigonal, and not tetragonal as erroneously supposed. A revaluation of the powder diffraction data listed in the scientific literature for uytenbogaardtite according to the structural results obtained here leads to an excellent agreement. Crystal-chemical features of uytenbogaardtite, Au2S, petrovskaite AgAuS, uytenbogaardtite–fischesserite series Ag3Au(S2–xSex) and acanthite–naummanite series Ag2(S1–xSex) are compared.

Cylas formicarius (F.) shows a strong overall sexual monomorophism, with external differences noted in only three organs: (a) relative size of the hind wings; (b) form of the antennal club and numbers of its different types of sensillum; and (c) size of the compound eyes and their individual facets. We relate these to known or predicted behavioural differences. Eye dimorphism is used to test a theoretical rule on the relationship between differences in overall eye size and in the size of individual ommatidia. Some sexually monomorphic features are briefly discussed, including two types of putatively sensory hairs not found on the antennae.