Critical raw materials (CRMs) are crucial for the transformation towards low carbon mobility. However, their production is often highly concentrated in a few countries, which leads to supply risks. Exemplified by the case of rare earth elements (REEs) and based on in-depth interviews with corporate executives from companies along the automotive supply chain, this contribution provides insights into the strategies of the European automotive industry to cope with these supply risks. Results show a lack of awareness of REE criticality studies and their outcomes in the past, the decisive role of price competitiveness when pursuing mitigation strategies and a lack of willingness or ability to engage in rare earth (RE) projects to get access to production output and secure supply. Overall, affected companies struggle to pursue long-term oriented strategies to secure their need for REEs. These findings are discussed with regard to the new demand for CRMs due to the shift to electric mobility and the specific challenges that the automotive industry faces.

This paper deals with a series of soil-clay minerals which have a widespread distribution in the north-east of Scotland. The original member is a biotite-like mica which breaks down readily in the soil into (i) a vermiculite or (ii) a montmorillonite, depending on the soil-forming conditions operating. Apart from this 'clay biotite' and its decomposition products, the main crystalline constituents of the Scottish soil-clays are a member of the kaolinite group and illite (' clay muscovite'). Iron and aluminium oxides are present in all the clays in the amorphous condition, but crystalline varieties are scarce. The distribution of the minerals and their relationship to the various soft-forming factors will form the subject of a separate communication; here, the nature of the clay minerals and their interrelationships are considered.

It is a familiar fact that in dikes, lava-flows, and sills the grain-size of the individual minerals normally varies according to the distance from the contacts. At or near the margins of the igneous body the grainsize is usually very much less than in the centre, and this phenomenon has been attributed to differences in the cooling-velocities at these spots. On the basis of measurements carried out by Queneau (8) the opinion seems to have been formed that the crystal-size always shows a progressive increase from the contacts towards the centre. This is not so, however, for as Lane (6) has shown, the crystal-size may increase to a maximum at a certain distance from the margin, and thereafter decrease again towards the centre of the intrusion. Apart from these investigations, carried out by Queneau and Lane, the only additioual quantitative data oil crystal-size variation known to the writer concerns a series of measurements made on an olivine-diabase by B. H. Dollen, under the direction of H. L. Alling.

Aleutite, ideally [Cu5O2](AsO4)(VO4)·(Cu0.5□0.5)Cl, was found in the Yadovitaya fumarole of the Second scoria cone of the Great Fissure Tolbachik eruption, Kamchatka Peninsula, Russia. Aleutite occurs as individual crystals in the masses of polycrystalline anhydrite. Aleutite is monoclinic, C2/m, a = 18.090(2) Å, b = 6.2284(6) Å, c = 8.2465(9) Å, β = 90.597(2)°, V = 929.1(2) Å3 and Z = 4 (from single-crystal X-ray diffraction data). The empirical formula calculated on the basis of (As + V+Mo + Fe3+) = 2 atoms per formula unit is Сu5.40Zn0.05Ca0.01As1.09V0.84Mo0.04Fe0.03K0.05Pb0.02Rb0.01Cs0.01O9.97Cl1.07. The crystal structure was solved by direct methods and refined to an agreement index R1 = 0.066. Aleutite has a new structure type. Aleutite is unique amongst natural and synthetic copper vanadates and arsenates, as it has As5+ and V5+ cations ordered over two tetrahedral sites. The topology of ${}_\infty ^1 [{\rm Cu_5O_2}]^{6 +} $ oxocentred bands in aleutite is novel and has not been described before in minerals and synthetic materials. The structural architecture of the ${}_\infty ^1 [{\rm Cu_5O_2}]^{6 +} $ band in aleutite can be derived from a kagome network and represents a one-dimensional slice from it. In addition, aleutite is an interesting and complex example of a natural salt-inclusion phase.

Cobaltite-cemented pyrite framboids are reported from the base of the Kupferschiefer in the Lubin-Sieroszowice mining district in southern Poland. In the framboids, cobaltite occurs interstitial to the pyrite crystals. The cobaltite-cemented framboids are confined to within a few cm either side of the boundary between the Weissliegendes sandstone and the Kupferschiefer laminated organic-rich shales. Textural relations and distribution of the cobaltite is interpreted as indicating that the framboids acted as a site of preferred cobaltite precipitation and that the cobaltite precipitated in response to the changing chemical environment at the Weissliegendes/Kupferschiefer contact. It is proposed that the texture may have formed as a result of desorption of Co and/or As which had been adsorbed onto the monosulphide precursors to the framboidal pyrite. Desorption during the transition to pyrite resulted in cobaltite saturation within the framboid and subsequent precipitation. The source of the Co and As was probably oxyhydroxides which exist in the upper oxic part of the Weissliegendes.

Electron diffraction and electron-microprobe investigations have revealed the presence of order in the monazite-huttonite series. Chemical analyses from the literature and electron-microprobe analyses in this study show that the monazite-huttonite series, REPO4-ThSiO4, is only continuous if the contribution of F, M2+, and OH to the charge balance is taken into account. The electron-diffraction study points to ordered domain structures in the series.

The new mineral nabimusaite, KCa12(SiO4)4(SO4)2O2F (R3m, a = 7.1905(4), c = 41.251(3) Å, V = 1847.1(2) Å3, Z = 3), has been discovered in larnite-ye' elimite nodules of pyrometamorphic rocks of the Hatrurim Complex. Nabimusaite is colourless, transparent with a white streak, has a vitreous lustre and does not show luminescence. It is brittle, but shows pronounced parting and imperfect cleavage along (001). Nabimusaite is uniaxial (–), ω = 1.644(2), ε = 1.640(2) (589 nm), nonpleochroic, Mohs' hardness is ∼5 and the calculated density is 3.119 g cm–3. The crystal structure has been solved and refined to R1 = 0.0416. Its artificial analogue is known. The nabimusaite structure may be derived from that of hatrurite, also known as the clinker phase 'alite' (C3S = Ca3SiO5), and is built up by an intercalation of three positively charged hatrurite-like modules of composition [Ca12(SiO4)4O2F]3+ with inserted modules of [K(SO4)2]3–. The hatrurite-like modules in nabimusaite are characterized by octahedrally coordinated anion sites and tetrahedrally coordinated cation sites. The structure is representative of the intercalated antiperovskite type. In contrast to its synthetic analogue, nabimusaite is P-bearing. The shortened bond T–O lengths for one tetrahedral site indicates P preference at the Si2 site, located at the border of the hatrurite-like modules. Significant variations of isomorphous substitutions in nabimusaite suggest the possibility of other isostructural minerals occurring in Nature. It also seems likely that nabimusaite could serve as a prototype for new advanced synthetic materials, given the discovery of two other new minerals in the Hatrurim Complex with related modular structures, placed in the nabimusaite group. These are zadovite and aradite, as described in a companion paper (Galuskin et al., 2015a).

The mineral assemblage and paragenesis of nabimusaite suggests that nabimusaite formed as a result of the reaction of potassium-enriched, sulfate-bearing melt with larnite and ellestadite. This contradicts the isochemical model that pyrometamorphic rocks of the Hatrurim Complex formed relatively fast in a practically dry system.

Alluvial rubies and sapphires are found in palaeodrainage deposits along the Cudgegong-Macquarie River system, central eastern New South Wales, Australia. A pink to red suite contains Cr (up to 0.6 wt.% Cr2O3) as the main chromophore, exceeding Fe (up to 0.5 wt.%Fe2O3). Corrosive etching suggests a prior xenocrystic Mesozoic-Cenozoic basaltic transport, while Cr2O3/Ga2O3 to Fe2O3/TiO2 ratios indicate an original metamorphic source. Syngenetic mineral inclusions include Al-rich diopside, meionite and anatase. The Al-rich diopside (‘fassaite’) contains extremely high Al2O3 (20–21 wt.%). A blue-green suite contains Fe (up to 0.8 wt.% Fe2O3) as a dominant chromophore, while a rare nepheline-anorthoclase composite inclusion supports a magmatic phonolitic origin. The Cudgegong- Macquarie ruby formation is compared with a garnet granulite origin proposed for Thailand rubies and a xenolith of corundum-bearing garnet granulite from Ruby Hill, Bingara, Australia. Clinopyroxenecorundum thermometry suggests the Cudgegong-Macquarie rubies formed at T >1000–1300ºC, a high equilibration T for proposed lithospheric granulites. These rubies form a distinctive suite compared to other rubies from Australian and SE Asian basalt fields, but have some similarities with eastern Thailand rubies.

The stratigraphical limits on the age of the Freetown intrusion, Sierra Leone, are very wide, yet the intrusion has not previously been accurately dated by isotopic methods, despite a number of attempts. Rubidium-strontium dating of acid veins contemporaneous with the early stages of the prolonged cooling history of the intrusion provides an age of 193 ± 3 Ma. The veins consist of quartz and orthoclase with relict minerals, principally plagioclase, from thehost gabbro. Electron-microprobe analysis of the altered minerals of the veins, and the petrography of the vein and adjacent host gabbro clearly demonstrate that the veins were formed from a granitic fraction, differentiated in situ from the surrounding solid gabbro with the assistance of a hydrous fluid phase within the incipient vein. This assertion is supported by the identical, low value of the initial 87Sr/86Sr ratio (0·70389) obtained from both the acid and basic rocks, and the technique described here may be useful in dating other, similar, intrusions.

The new minerals bobcookite (IMA 2014-030), NaAl(UO2)2(SO4)4·18H2O and wetherillite (IMA 2014-044), Na2Mg(UO2)2(SO4)4·18H2O, were found in the Blue Lizard mine, San Juan County, Utah, USA, where they occur together as secondary alteration phases in association with boyleite, chalcanthite, dietrichite, gypsum, hexahydrite, johannite, pickeringite and rozenite.

Bobcookite descriptive details: lime green to greenish-yellow massive veins and columnar crystals; transparent; vitreous lustre; bright greenish-white fluorescence; pale greenish yellow streak; hardness (Mohs) 2½; brittle; conchoidal fracture; no cleavage; moderately hygroscopic; easily soluble in cold H2O; densitycalc = 2.669 g cm–3. Optically, biaxial (–), α = 1.501(1), β = 1.523(1), γ = 1.536(1) (white light); 2Vmeas. = 78(1)°; 2Vcalc. = 74°; dispersion r < v, moderate. Pleochroism: X colourless, Y very pale yellow-green, Z pale yellow-green; X < Y < Z. EDS analyses yielded the empirical formula Na0.97Al1.09(U1.02O2)2(S0.98O4)4(H2O)18. Bobcookite is triclinic, P1, a = 7.7912(2), b = 10.5491(3), c = 11.2451(8) Å , α = 68.961(5), β = 70.909(5), γ = 87.139(6)°, V = 812.79(8) Å3 and Z = 1. The structure (R1 = 1.65% for 3580 Fo > 4σF) contains [(UO2)(SO4)2(H2O)] chains linked by NaO4(H2O)2 octahedra to form layers. Hydrogen bonds to insular Al(H2O)6 octahedra and isolated H2O groups hold the structure together. The mineral is named for Dr Robert (Bob) B. Cook of Auburn University, Alabama, USA.

Wetherillite descriptive details: pale greenish-yellow blades; transparent; vitreous lustre; white streak; hardness (Mohs) 2; brittle; two cleavages, {101} perfect and {010} fair; conchoidal or curved fracture; easily soluble in cold H2O; densitycalc = 2.626 g cm–3. Optically, biaxial (+), α = 1.498(1), β = 1.508(1), γ = 1.519(1) (white light); 2Vmeas. = 88(1)°, 2Vcalc. = 87.9°; dispersion is r < v, distinct; optical orientation: Z = b, X ∧ a = 54° in obtuse β; pleochroism: X colourless, Y pale yellow-green, Z pale yellow-green; X < Y ≈ Z. EDS analyses yielded the empirical formula Na1.98(Mg0.58Zn0.24Cu0.11Fe0.092+)Σ1.02(U1.04O2)2(S0.98O4)4(H2O)18. Wetherillite is monoclinic, P21/c, a = 20.367(1), b = 6.8329(1), c = 12.903(3) Å, β = 107.879(10)°, V = 1709.0(5) Å3 and Z = 2. The structure (R1 = 1.39% for 3625 Fo > 4σF) contains [(UO2)(SO4)2(H2O)] sheets parallel to {100}. Edge-sharing chains of Na(H2O)5O polyhedra link adjacent uranyl sulfate sheets forming a weakly bonded three-layer sandwich. The sandwich layers are linked to one another by hydrogen bonds through insular Mg(H2O)6 octahedra and isolated H2O groups. The mineral is named for John Wetherill (1866–1944) and George W. Wetherill (1925–2006).

An experimental study of an Al-rich schorl sample from Cruzeiro mine (Minas Gerais, Brazil) was carried out using electron microprobe analysis, structural refinement and Mössbauer, infrared and optical absorption spectroscopy in order to explore the disordering of Fe2+ over the Y and Z sites of the tourmaline structure.

A structural formula was obtained by merging chemical and structural data. The cation distribution at the two non-equivalent octahedrally coordinated sites (Y and Z) was obtained by two different optimization procedures which, minimizing the residuals between observed and calculated data, converged to the formula: X(Na0.65〈0.32Ca0.02K0.01)Σ1.00Y(Fe1.652+Al1.15Fe0.063+Mn0.052+Zn0.05Ti0.044+)Σ3.00Z(Al5.52Fe0.302+Mg0.18)Σ6.00[T(Si5.87Al0.13)Σ6.00O18](BBO3)3V(OH)3W[(OH)0.34F0.28O0.38]Σ1.00.

This result shows a partial disordering of Fe2+ over the Y and Z sites which explains adequately the mean atomic number observed for the Z site (13.5±0.1). Such a disordering is also in line with the shoulder recorded in the Mössbauer spectrum (fitted by a doublet with isomer shift of 1.00 mm/s and quadrupole splitting of 1.38 mm/s) as well as with the asymmetric bands recorded in the optical absorption spectrum at ∼9000 and 14,500 cm–1 (modelled by four Gaussian bands, centred at 7677 and 9418 cm–1, and 13,154 and 14,994 cm–1, respectively).

The high degree of consistency in the results obtained using the different methods suggests that the controversy over Fe2+ order can be ascribed to the failure to detect small amounts of Fe2+ at Z (typically <<10% atoms/site) rather than a steric effect of Fe2+ on the tourmaline structure.

Pectolite has been identified, using petrographic, chemical, and X-ray methods, in kimberlites from the De Beers and Dutoitspan Mines, Kimberley, South Africa and the Letseng-La-Terai Mine, Lesotho. It occurs as radiating aggregates of fibrous or acicular crystals not only in the groundmass of certain kimberlites but also in altered xenoliths included within kimberlite. The occurrence of Na-rich minerals in kimberlite is unusual. It is suggested that it can occur as an apparently primary mineral resulting from the incorporation and assimilation of foreign Na-bearing material prior to final consolidation, and/or as a secondary mineral after metasomatic introduction of Na-bearing fluids.

Meisserite (IMA2013-039), Na5(UO2)(SO4)3(SO3OH)(H2O), is a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah (USA). It is named in honour of the prominent Swiss mineralogist Nicolas Meisser. The new mineral was found in a sandstone matrix and is associated with chalcanthite, copiapite, ferrinatrite, gypsum, johannite and another new Na-bearing uranyl sulfate, belakovskiite (IMA2013-075). Meisserite is a secondary mineral formed by the post-mining weathering of uraninite. The mineral is triclinic, P, a = 5.32317(10), b = 11.5105(2), c = 13.5562(10) Å, α = 102.864(7)°, β = 97.414(7)°, γ = 91.461(6)°, V = 801.74(6) Å3, and Z = 2. Crystals are prisms elongated on [100], up to 0.3 mm long, exhibiting the forms {010} and {001}. Meisserite is pale green to yellowish green, translucent to transparent and has a very pale yellow streak. It is brittle, with fair cleavage on {100} and {001}, and uneven fracture. The Mohs hardness is estimated at 2. Meisserite is somewhat hygroscopic and easily soluble in water. The calculated density based on the empirical formula is 3.208 g/cm3. Meisserite exhibits bright yellow green fluorescence under both long- and shortwave UV radiation. The mineral is optically biaxial (–), with α = 1.514(1), β = 1.546(1), γ = 1.557(1) (measured in white light). The measured 2V is 60(2)° and the calculated 2V is 60°. Dispersion is r > v, perceptible, and the optical orientation is X ≈ a, Z ≈ c*. The mineral is pleochroic, with X (colourless) < Y (pale yellow) ≈ Z (pale greenish yellow). The empirical formula of meisserite (based on 19 O a.p.f.u.) is Na5.05(U0.94O2)(SO4)3[SO2.69(OH)1.31](H2O). The Raman spectrum is dominated by the symmetric stretching vibrations of UO22+, SO42– and also weaker O–H stretching vibrations. The eight strongest powder X-ray diffraction lines are [dobs in Å (hkl)Irel]: 13.15 (001) 81, 6.33 (02) 62, 5.64 (01,020) 52, 5.24 (100,012,01) 100, 4.67 (101) 68, 3.849 (1,102,022) 48, 3.614 (02,3) 41, and 3.293 (13,004) 43. The crystal structure of meisserite (R1 = 0.018 for 3306 reflections with Iobs > 3σI) is topologically unique among known structures of uranyl minerals and inorganic compounds. It contains uranyl pentagonal bipyramids linked by SO4 groups to form chains. Na+ cations bond to O atoms in the chains and to an SO3OH group and an H2>O group between the chains, thereby forming a heteropolyhedral framework.

The present communication deals with a peculiar series of rocks found in association with the Tertiary sediments so extensively developed in south-west Persia at the head of the Persian Gulf. At one or two localities in that region the marls and limestones are baked, fused, and in some cases so thoroughly recrystallized that at one time they were suspected to be igneous material arising from localized volcanic action. Careful examination of the field occurrences has, however, failed to disclose any trace of volcanicity, whilst petrographical and chemical examination has shown that even the most coarsely crystalline types bear no resemblance to any known igneous rock.

My attention was first directed to these rocks by Mr. H. T. Mayo in 1926 when I was permitted to examine the material collected by Mr. B. K. N. Wyllie, to whom belongs the credit of first discovering these apparently unique occurrences, and to visit the localities, where additional material was obtained. The cause of the alteration of the sedimentary rocks at these localities is no longer operative, and is not apparent; that it may most probably be ascribed to the combustion of gas or oil long since extinguished has been made clear by the subsequent investigation of other localities where similar rocks have been, and are being, exposed to such action and have undergone similar changes in structure and mineral composition.

Green calcium sulphosilicate layers were formed in lime-larnite-calcite wall coating in a lime kiln at Rivervale, Western Australia. The compound formed in the kiln flame area by the combination of siliceous lime sand feed with sulphur trioxide from the sulphurous oil fuel.

The calcium sulphosilicate is orthorhombic with a 10·183, b 15·408, c 6·825 Å, space group Pcmn. Crystals are [100] tablets or prisms elongated along c, D 2·95, hardness 5, streak pale green, decomposed by organic acids. Optical properties α 1·632 = [001] blue, β 1·638 = [100] yellow-green γ 1·640 yellow-green, 2Vα = 60°, dispersion r > v, X-ray powder lines: 2·855 (10) 032,202; 2·838 (7) 330,321; 3·35 (6) 012; 2·622 (6) 331; 2·571 (6) 060; 3·20 (5) 231; 1·962 (5); 1·899 (5); 1·896 (5); 1·372 (5).

Chemical analysis by P. Hewson gave: SiO2 21·50, Al2O3 1·83, Fe2O2 0·50, CO2 0·49, P2O5 0·23, CaO 57·19, MgO 0·35, Na2O 0·22, K2O 0·22, SrO 0·15, Li2O 0·06, SO3 16·71, H2O+ 0·28, H2O− 0·10, others 0·04, total 99·87. On a water-free basis the unit cell contains Ca19.66 Mg0.17 Na0.14 K0.08 Sr0.03 Li0.08 approximately 4[Ca5(SiO4)2SO4] and isostructural with silicocarnotite, 4[Ca5(PO4)2SiO4]. Type material is preserved at the Government Chemical Laboratories, Perth, Western Australia.

We have imaged the spatially-preserved microtexture of biogenic apatite, retained together with its collagen template, in non-demineralized human bone using high-resolution transmission electron microscopy. Using ion-beam thinning, a specimen preparation method generally employed for inorganic minerals rather than for biological materials, we have imaged a composite nanostructure of bone not previously reported, and we propose a model for this nano-architecture that involves a boxconstruction of apatite plates and apatite sheets. This observation provides a new understanding of bone strength at the nanometre scale and suggests how post mortem enhancement of this texture by recrystallization probably accounts for the durability of ancient bone. Modern sheep bone (a close analogue for recently dead human bone) imaged in the same way also shows evidence of this composite architecture.

This paper highlights new research on the biomineralization of otoliths and uses a mineralogical approach to understand mechanisms of crystal growth and metal incorporation into otoliths. Petrographic observations of the nucleation of otolith growth in the core for several fish species reveals that sagittal otoliths appear to nucleate around a few or many nucleation sites (primordia) and that these sites vary in size (ranging in diameter from 1 to 20 μm), depending on the species. Spectroscopic data show a large Mn-enrichment in the primordia within the core but the reasons for this enrichment are still unclear (e.g. organic matter or possibly another material other than CaCO3). This study also provides the first multi trace-element data for endolymph fluid and the growing otolith; we found large enrichments (Ca and Sr) and depletions (Na, K, Zn and Rb) of elements in the otolith relative to the endolymph. The last part of this paper examines the effect of crystal structure on the microchemistry ofotoliths. Our investigation helps understand how the chemical characteristics of the metal ions (i.e. ionic radii) and the crystalline structure interact to cause differential trace-metal uptake between the CaCO3 polymorphs, aragonite and vaterite.

An investigation into the relative stabilities and equations of state of stoichiometric FeS was conducted using first-principles pseudopotential calculations. These calculations were based on density functional theory and performed using ultrasoft Vanderbilt pseudopotentials within the generalized gradient approximation. We have identified four stable polymorphs of FeS along the 0 K isotherm as a function of pressure: troilite, an orthorhombic MnP-type structure, a monoclinic structure, and a CsCl-type structure. The calculated internal energy as a function of volume for each polymorph was fitted to 4th order logarithmic and 3rd order Birch-Murnaghan equations of state, yielding values for the bulk modulus, K, and its first and second derivatives with respect to pressure, K′ and K″. These equations of state may be used to characterize models of planetary cores.

Petrological and mineral chemical data are presented for two new occurrences of co-existing borosilicate minerals in the Larsemann Hills, East Antarctica. The assemblages contain kornerupine and the rare borosilicate, grandidierite (Mg,Fe)A13BSiO9. Two distinct associations occur: (1) At McCarthy Point, 1–10 mm thick tourmaline-kornerupine-grandidierite layers are hosted within quartzofeldspathic gneiss; and (2) Seal Cove, where coexisting kornerupine and grandidierite occur within coarse-grained, metamorphic segregations with Mg-rich cores of cordierite-garnet-spinel-biotite-ilmenite and variably developed plagioclase halos. The segregations are hosted within biotite-bearing, plagio-feldspathic gneiss. Textural relationships from these localities indicate the stability of co-existing kornerupine and grandidierite.

The grandidierite- and kornerupine-bearing segregations from Seal Cove largely postdate structures developed during a crustal thickening event (D2) which was coeval with peak metamorphism. At McCarthy Point, grandidierite, kornerupine and late-tourmaline growth predates, or is synchronous, with F3 fold structures developed during a extensive granulite grade, normal shearing event (D3) which occurred prior to, and synchronous with, near-isothermal decompression. Average pressure calculations on assemblages that coexist with the borosilicates at Seal Cove, indicate the prevailing conditions were 5.2–5.5 kbar at ∼ 750°C for formation of the grandidierite-kornerupine assemblage.

Electron microprobe analysis of the new mineral scotlandite yielded Pb 72.27, S 9.95, corresponding to PbO 77.85, SO2 19.88, sum 97.73 wt.%. Secondary ion mass spectrometry showed the absence of Li, Be, B, C, N, and F, but the presence of very small amounts of Br. Infrared spectroscopy showed that the mineral is a sulphite with neither OH nor any other polyatomic anions. The empirical formula, calculated on the basis of Pb+S = 2 is Pb1.06S0.94O2.94 or ideally PbSO3.

The mineral has the following vibrations of the sulphite ion in the infrared spectrum: v3 920, 865; v1 970 (?); v2 620, 600; v4 488, 470 cm−1.

Scotlandite is monoclinic, with possible space groups P21 or P21/m. The unit cell dimensions are: a 4.542(2), b 5.333(2), c 6.413(2) Å, β 106.22(4)°, Z = 2. The strongest lines in the powder diffraction pattern are: 3.99(10) (011), 3.38(7) (110), 3.25(8) (11), 3.07(4) (002), 2.66(7) (020, 012), 2.56(4) (11), 2.24(5) (12, 102), 2.01(5)(210, 022), 1.707(4) (031), 1.538(4) (032, 004).

Scotlandite occurs as chisel-shaped or bladed crystals elongated along the c-axis, with a tendency to form radiating clusters. The following forms have been determined: {100}, {010}, {011}, {021}, {031}, and {032}. The new mineral has a pronounced cleavage along {100}, and a less good one along {010}. The crystals are pale yellow to greyish-white and colourless, sometimes transparent. Their lustre is adamantine, pearly on cleavage planes.

The mineral is optically biaxial positive, 2Vmeas. 35° 24' (Na). The refractive indices are: α ~ 2.035, β ~ 2.040, and γ ~ 2.085 (Na). Dispersion is strong, v >> r. The extinction is β//b, and α [001] = 20° (γ: [100] = 4°) in the obtuse angle β. H (Mohs) ≤ 2. D = 6.37 and calculated Dx = 6.40 g cm-3.

Scotlandite occurs in cavities in massive baryte and anglesite, and is closely associated with lanarkite and susannite; it represents the latest phase in the crystallization sequence of the associated lead secondary minerals. The label locality of the specimen is the Susanna vein, Leadhills, Scotland.