The search for biosignatures of past microbial life has promoted the interest in halophilic archaea trapped inside fluid inclusions of salt crystals. These hypersaline environments are promising targets for the preservation of microbial cell envelope biomolecules. In this study, we focused on the preservation of bacterioruberin, a carotenoid pigment found in the cell envelope of Halobacterium salinarum, within fluid inclusions of salt crystals mimicking early Mars environments and modern Earth. Halite (NaCl) and sylvite (KCl) crystals were subjected to Mars-like proton irradiation, and the preservation of carotenoids was assessed using in situ and ex situ Raman spectroscopy. Our findings demonstrate that Raman spectroscopy efficiently detected carotenoids within fluid inclusions in non-irradiated crystals. However, post-irradiation analyses posed great challenges due to fluorescence induced by the formation of colour centres in the crystal lattice, which suppressed the carotenoid signal. Cleavage of irradiated crystals revealed preserved carotenoid pigments beyond the radiation penetration depth, suggesting potential preservation of biomolecules in deeper inclusions within larger crystals. Furthermore, in some cases, carotenoids were detected even within fluorescent zones, suggesting extensive preservation. This study underscores the potential of Raman spectroscopy for the detection of carotenoids as biosignatures in planetary exploration contexts, particularly as a preliminary screening tool. However, it also highlights the need for optimized protocols to overcome fluorescence-related limitations. These findings contribute to the methodologies for detecting and interpreting biosignatures in salt deposits, advancing the search for possible traces of past microbial life beyond Earth.

Allanite-(Y), ideally CaY(Al2Fe2+)(Si2O7)(SiO4)O(OH), is a valid species with the type locality in the Åskagen pegmatite, Värmland, Sweden. The mineral occurs as an accessory phase in the blocky zone of the NYF granitic pegmatite near Åskagen, Värmland, Sweden. It forms rims together with iimoriite-(Y), gadolinite-(Y) and allanite-(Nd) around altered crystals of thalénite-(Y). Allanite-(Y) replaced primary thalénite-(Y) during an episode of early post-magmatic hydrothermal activity. Allanite-(Y) forms euhedral crystals with size up to 1 mm, black with a vitreous lustre, conchoidal fracture and greyish brown streak. It has a Mohs hardness of ca. 6, the calculated density of 3.945 g.cm–3 and is biaxial (−) with α = 1.760(3), β = 1.799(2) and γ = 1.784(3) in 589 nm light; pleochroism is weak pale yellowish brown in all directions. Allanite-(Y) has monoclinic symmetry, with the space group P21/m, a = 8.8520(8) Å, b = 5.6959(5) Å, c = 10.0543(9) Å, β = 115.510(2)°, V = 457.52(7) Å3 and Z = 2. Crystal-chemical analysis resulted in the empirical formula: A1(Ca0.900Mn0.090Na0.010)Σ1.000A2(Y0.323Ca0.260Nd0.118Sm0.087Gd0.098Dy0.044Ce0.034Pr0.014Tb0.012Er0.005La0.003Ho0.002Yb0.001)Σ1.001M1(Al0.921Fe2+0.070Ti0.003)Σ0.994M2(Al1.000)M3(Fe2+0.638Fe3+0.262Al0.072Mg0.028)Σ1.000T1(Si1.000)T2(Si1.000)T3(Si1.003)O12.000(OH)1.000.

Allanite-(Y) belongs to the allanite group of the epidote supergroup. The closest end-member compositions of valid allanite group species are allanite-(Ce), allanite-(La) and allanite-(Nd) related via the simple exchange mechanism Y ↔ Ln. The allanite-(Y) origin during metasomatic replacement of the thalénite-(Y) was mainly affected by local system composition and structural constraints rather than Ln+Y fluoride complexation in hydrothermal solution.

A new oxalate mineral species, edwindavisite, ideally Cu(C2O4)(NH3), was discovered in specimens collected from the Rowley mine, Maricopa County, Arizona, USA. It occurs as fans or sprays of bladed or prismatic crystals (up to 0.50 × 0.08 × 0.06 mm), associated intimately with ammineite, a sampleite-like mineral, baryte, ebnerite, wulfenite and quartz. Edwindavisite is green, transparent with a pale green streak and has a vitreous lustre. It is brittle and has a Mohs hardness of ∼2; cleavage is perfect on {100}. No parting or twinning was observed. The measured and calculated densities are 2.55(2) and 2.53 g/cm3, respectively. Optically, edwindavisite is biaxial (+), with α = 1.550(2), β = 1.559(2), γ = 1.755(5), 2Vmeas. = 26(2)° and 2Vcal. = 26.4°. Electron microprobe analyses yielded the empirical formula (based on Cu = 1 apfu) Cu1.00(C2O4)(NH3)0.99.

Edwindavisite is the natural counterpart of synthetic catena-μ-oxalato-ammine-copper(II), Cu(C2O4)(NH3). It is orthorhombic with space group Pbca and unit-cell parameters a = 11.1998(10), b = 9.4307(9), c = 8.3977(7) Å, V = 886.98(14) Å3 and Z = 8. In the edwindavisite structure, each Cu2+ cation is coordinated by (5O + N), forming a rather distorted and elongated octahedron. The Cu-octahedra share corners with one another to form chains extending along [001], which are joined together by oxalate (C2O4)2– groups, giving rise to layers parallel to (100). These layers are linked together by N–H···O hydrogen bonds. Among 37 oxalate minerals documented to date, edwindavisite is the first one that contains ammonia (NH3).

The new ixiolite-group mineral nioboixiolite-(Fe3+), ideally (Nb0.5Fe3+0.5)O2, was discovered in nosean sanidinite of the Laach Lake (Laacher See) volcano, Eifel region, Rhineland-Palatinate, Germany. The associated minerals are sanidine, K-bearing albite, nosean, biotite, Nb-rich ilmenite, Ti-rich magnetite, hercynite, corundum, samarskite-(Y), ekebergite and columbite-(Fe). Nioboixiolite-(Fe3+) forms long prismatic to acicular crystals up to 0.03 × 0.06 × 1 mm and epitaxial intergrowths with ilmenite and intermediate members of the samarskite–ekebergite series. Both colour and streak are black and the lustre is submetallic. The new mineral is brittle, with the Vickers’ micro-indentation hardness of 499 kg mm–2 which corresponds to the Mohs’ hardness of 5. No cleavage is observed. The fracture is conchoidal. The calculated density is 5.033 g·cm–3. In reflected light, nioboixiolite-(Fe3+) is grey, no pleochroism is observed. The reflectance values (Rmin, %/Rmax, %/λ, nm) are: 14.7/16.4/470, 14.3/15.9/546, 14.1/15.7/589 and 14.0/15.8/650. The Raman spectrum shows bands corresponding to stretching vibrations of (Nb,Ti)–O–(Nb,Ti) and (Nb,Ti)–O–Mn2+ and the absence of bands of OH groups. The chemical composition is (electron microprobe data, wt.%): MgO 0.41, MnO 3.52, Al2O3 0.42, Cr2O3 0.75, Fe2O3 20.23, TiO2 22.26, ZrO2 0.76, Nb2O5 51.82, total 100.17. The empirical formula is (Mg0.04Mn2+0.20)Σ0.24(Al0.03Cr0.04Fe3+1.01)Σ1.08(Ti1.11Zr0.02)Σ1.13Nb1.55O8 (Z = 1). The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 3.586 (29) (110), 2.917 (100) (111), 2.503 (18) (002), 2.170 (18) (121), 1.738 (22) (130), 1.689 (26) (221). The crystal structure was determined using single-crystal X-ray diffraction data and refined to R = 0.0447. Nioboixiolite-(Fe3+) is orthorhombic with space group Pbcn, a = 4.6578(6), b = 5.6230(7), c = 5.0182(5) Å and V = 131.43(3) Å3. The new mineral is isostructural with other members of the ixiolite group.

Nancyrossite, ideally FeGeO6H5, is a new hydroxyperovskite from Tsumeb. It probably formed by the oxidation and partial dehydrogenation of stottite, FeGe(OH)6, with which it is associated intimately. The structure of nancyrossite has been determined in tetragonal space group P42/n: a = 7.37382(12) Å, c = 7.29704(19) Å, V = 396.764(16) Å3, Z = 4, R1(all) = 0.034, wR2(all) = 0.051 and GoF = 1.057. Empirical formulae of two crystals have almost end-member compositions, Fe3+1.01Zn0.03Ge0.98O6H5 and Fe3+1.01Zn0.04Ge0.98O6H5. Structure determination indicates that 88% of the Fe is ferric. The chemical formula proposed here for nancyrossite recognises that although H atoms form OH groups, writing the formula as FeGeO(OH)5 implies that one of the six oxygen atoms is very underbonded, with a bond-valence sum of only ∼1.2 valence units. As such, H in nancyrossite may have novel crystal chemistry. For example, the five H atoms may be distributed dynamically over the six O atoms, a phenomenon that would be averaged by X-ray diffraction, and so go undetected. Nancyrossite is the Ge-analogue of jeanbandyite. By analogy with nancyrossite, we propose revision of the ideal formula of jeanbandyite from FeSnO(OH)5 (Welch and Kampf, 2017) to FeSnO6H5.

Two alluaudite-group minerals, badalovite, ideally NaNaMg(MgFe3+)(AsO4)3, and calciojohillerite, NaCaMgMg2(AsO4)3, have been identified on a specimen from the Monte Calvario quarry, Biancavilla, Etna volcanic complex, Sicily, Italy. For both species, this finding represents the second world occurrence. The studied sample was characterised using electron microprobe analysis, micro-Raman spectroscopy, and single-crystal X-ray diffraction. Badalovite occurs as vitreous to resinous aggregates of yellowish to brownish prismatic crystals, up to 0.5 mm in length, associated with tabular crystals of hematite, pseudobrookite and an amphibole-supergroup mineral. Badalovite is intimately intergrown with minor calciojohillerite. The chemical formulae of these two alluaudite-group members, recalculated on the basis of 12 O atoms per formula unit and assuming the occurrence of Fe3+, are (Na1.74(11)K0.01(1)Ca0.30(8))Ʃ2.05(Mg1.74(2)Mn0.27(2)Ca0.11(8)Zn0.03(1)Fe0.84(14)Al0.02(2))Ʃ3.01(As2.85(4)P0.11(3))Ʃ2.96O12 and (Na1.44(2)K0.01(1)Ca0.66(1))Ʃ2.11(Mg2.27(1)Mn0.28(1)Zn0.01(1)Fe0.48(2))Ʃ3.00(As2.79(3)P0.13(2))Ʃ2.92O12, respectively. Single-crystal X-ray diffraction data collected on badalovite gave the following unit-cell parameters a = 11.9760(5), b = 12.7857(5), c = 6.6650(3) Å, β = 112.689(2)°, V = 941.58(7) Å3, space group C2/c. Its crystal structure was refined to R1 = 0.0257 for 1711 unique reflections with Fo > 4σ(Fo) and 97 least-square parameters. The crystal chemical and spectroscopic data as well as the genesis of badalovite are discussed and a comparison with the Russian type material is reported.

Members of norsethite-type carbonate solid solutions with the compositions Ba(Mg1–xMnx)(CO3)2, (x = 0, 0.25, 0.50 and 0.75) have been synthesised under high-pressure and -temperature conditions (3GPa, 800°C) for the first time. The synthetic transparent crystals gradually changed their appearance from colourless to blue lustre with the increasing Mn2+ content (XMn). The results of the crystal structure analyses reveal that the lattice parameters (a, c, unit-cell volume, Mg/Mn–O bond lengths and Ba–O bond lengths) complied with a linear increase with XMn. In contrast, the C–O bond lengths and O–C–O bond angles decreased, because the CO32– group was squeezed by the expansion of the (Mg/Mn)O6 octahedra. Moreover, the Raman and infrared vibrations, except for the lattice mode T, shift to low frequency with the increasing XMn, and the slight corresponding variations of the atomic positions were also determined. These new results demonstrate the impact of Mg2+–Mn2+ substitution on the crystal chemistry of norsethite-type solid solutions, with further implications for the natural occurrence and environmental of norsethite-type and dolomite/ankerite-type carbonates.

The sulfide-free metasomatic rocks with chalcophile metals from the Nežilovo ore field, near Veles, Republic of North Macedonia belong to a rare kind of ore. The mineralogy and petrology of these rocks were studied in detail and can be considered as a standard description for ores of this type. A characteristic feature of Nežilovo-type ores is a wide variety of accessory oxide minerals containing chalcophile elements (Zn, Pb, Sb, Cu and As). The new nolanite-supergroup mineral zincorinmanite-(Zn), ideally (Fe3+2Zn)SbZnO7(OH), was discovered in the Nežilovo ore. The associated minerals are quartz, baryte, gahnite, Zn-bearing phlogopite, together with accessory hematite, almeidaite, a Pb-analogue of hydroxycalcioroméite and an insufficiently studied Sb-rich högbomite-supergroup mineral. Zincorinmanite-(Zn) forms lamellar to tabular subhedral single-crystal grains up to 0.5 mm across and up to 40 μm thick. The colour and streak are black and the lustre is submetallic. The new mineral is brittle, with the Mohs’ hardness of 6. No cleavage is observed. The fracture is uneven. The calculated density is 5.446 g·cm–3. In reflected light, zincorinmanite-(Zn) is light grey, no pleochroism is observed. The reflectance values (Rmin, %/Rmax, %/λ, nm) are: 12.6/13.7/470, 12.1/13.2/546, 11.8/12.8/589 and 11.5/12.2/650. The Raman spectrum shows bands corresponding to the O–H and Sb–O stretching vibrations and (Fe3+,M2+)–O–H bending modes. The chemical composition is (electron microprobe data, with iron divided into Fe2O3 and FeO based on the charge balance and H2O calculated from the structural data, wt.%): MgO 1.42, MnO 0.44, FeO 2.04, ZnO 22.55, Al2O3 1.95, Fe2O3 35.59, TiO2 1.51, Sb2O5 33.05, H2O 1.18, total 99.73. The empirical formula is [(Fe3+2.12Al0.18)(Zn0.32Mg0.16Fe2+0.13Mn0.03)Ti0.06]Σ3.00(Sb0.97Ti0.03)Σ1.00Zn1.00O7[(OH)0.61O0.39]Σ1.00. The crystal structure was determined using single-crystal X-ray diffraction data and refined to R = 0.0191. Zincorinmanite-(Zn) is hexagonal, space group P63mc, a = 5.9720(1), c = 9.3578(1) Å and V = 289.031(8) Å3 (Z = 2). The new mineral is isostructural with other members of the nolanite group. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) – hkl] are: 5.176 (46) – 100; 3.473 (77) – 102; 2.989 (46) – 110; 2.674 (86) – 103; 2.520 (100) – 112; and 2.496 (42) – 201.

The new mineral manganonewberyite (IMA2024–004), Mn(PO3OH)(H2O)3, was found underground at the Cassagna mine, Liguria, Italy, where it is a secondary phase formed by the interaction of bat guano with Mn-rich rock. Manganonewberyite occurs with niahite, kutnohorite, sampleite and serrabrancaite on a tinzenite–quartz–braunite matrix. Crystals are prisms and blades, up to ∼0.15 mm long, elongated parallel to [001], flattened on {100} and exhibiting the forms {100}, {010} and {111}. Crystals are colourless and transparent, with vitreous lustre and white streak. The mineral is brittle with curved fracture. The Mohs hardness is ∼3. Cleavage is perfect on {010}. The density is 2.34(2) g·cm–3. Optically, manganonewberyite is biaxial (+) with α = 1.541(2), β = 1.547(2) and γ = 1.559(2) (white light). The 2V is 71.6(3)°. The optical orientation is X = a, Y = b and Z = c. The empirical formula is (Mn0.960Mg0.016Ca0.015)Σ0.991(H1.02P1.00O4)(H2O)3. Manganonewberyite is orthorhombic, space group Pbca, with cell parameters: a = 10.4273(6), b = 10.8755(8), c = 10.2126(4) Å, V = 1158.13(11) Å3 and Z = 8. The crystal structure (R1 = 2.79% for 892 I > 2σI reflections) is the same as that of newberyite with Mn in place of Mg.

Neotype material of chukhrovite-(Ce), ideally (Ca3Ce)[AlF6]2(SO4)F·12H2O, was established on the basis of a new occurrence from the Tripi mine, Alì, Peloritani Mountains, Sicily, Italy. In fact the Russian specimens originally considered as type material of this species were later found to correspond to Ce-rich chukhrovite-(Y). At the Tripi mine, chukhrovite-(Ce) occurs as white cube-octahedral crystals, up to 0.05 mm in size, associated with creedite, quartz and fluorite. Electron microprobe analysis gave (in wt.%, normalised to sum = 100.00): SO3 8.40, P2O5 0.16, ZrO2 0.12, Al2O3 11.95, Y2O3 0.48, La2O3 3.64, Ce2O3 7.63, Pr2O3 1.00, Nd2O3 3.23, Sm2O3 0.97, Eu2O3 0.13, Gd2O3 0.97, Dy2O3 0.21, CaO 20.47, F 22.09, Cl 0.07, O = (F, Cl) –9.31, H2Ocalc 27.80. On the basis of 29 anions per formula unit, assuming the presence of 13 (F+Cl+OH) atoms and 12 H2O groups, the empirical formula of chukhrovite-(Ce) from the Tripi mine is Ca3.17(Ce0.40La0.19Nd0.17Pr0.05Sm0.05Gd0.05Y0.04Eu0.01Dy0.01)Σ0.97Zr0.01Al2.04(S0.91P0.02)Σ0.93O4[F10.10Cl0.02(OH)2.88]Σ13.00·12H2O. The occurrence of H2O groups was supported by micro-Raman spectroscopy. Chukhrovite-(Ce) is cubic, Fd$\bar 3$, with a = 16.7608(5) Å, V = 4708.5(4) Å3 and Z = 8. Its crystal structure was refined to R1 = 0.0378 for 604 unique reflections with Fo > 4σ(Fo) and 36 least-square parameters. Chukhrovite-(Ce) belongs to the chukhrovite group and it is isotypic with chukhrovite-(Y), whereas it is homeotypic with chukhrovite-(Ca).

A calcium-silicate xenolith (no. 11) from the ignimbrite of the Upper Chegem Caldera in Kabardino-Balkaria, Russia, has revealed a diverse mineral assemblage with As- and B-bearing phases from the apatite supergroup such as the svabite and johnbaumite–hydroxylellestadite series, in addition to cahnite and datolite. Three distinct zones of variable arsenic content have been investigated. Notably, the outermost altered zone adjacent to the ignimbrite hosts the highest concentration of arsenic and arsenate minerals. A detailed structural analysis using Raman spectroscopy was carried out to investigate the distribution of boron and arsenic in tetrahedral coordination. This has provided the basis for describing a solid-solution system between hydroxylellestadite, svabite and johnbaumite and can be used as a novel technique for identifying apatite-supergroup minerals. One aim of the analysis was to elucidate the origin of various elements and content levels, particularly in relation to the distance from the xenolith–ignimbrite contact. The presence of boron and arsenic, probably derived from ignimbrites, highlights the important role of volcanic rocks as potential contributors of these elements in mineral formation processes.

The new mineral zincostottite (IMA2024-024), ZnGe(OH)6, was found on specimens from the Tsumeb mine, Tsumeb, Namibia, where it is a secondary oxidation-zone mineral. It occurs as heavily etched remnants of equant or tabular crystals, up to ∼1 mm in diameter. Crystals are colourless and transparent, with vitreous to subadamantine lustre and a white streak. The mineral is brittle with irregular stepped fracture. The Mohs hardness is ∼4.5. Cleavage is good on {100} and poor on {001}. The calculated density is 3.834 g·cm–3. Optically, zincostottite is uniaxial (–) with ω = 1.785(5) and ε = 1.765(5) (white light). The empirical formula is (Zn0.77Fe3+0.23)Σ1.00Ge1.00O6H5.77. Zincostottite is tetragonal, space group P42/n, with cell parameters: a = 7.4522(18), c = 7.4000(8) Å, V = 411.0(2) Å3 and Z = 4. The crystal structure (R1 = 2.65% for 452 I > 2σI reflections) is the same as that of stottite with Zn in place of Fe2+

Manuelarossiite, ideally CaPbAlF7, is a new fluoride mineral found in a specimen from a fumarole formed subsequent to the 1944 eruption of the Vesuvius volcano, Naples Province, Campania, Italy. It occurs as very rare tabular crystals, up to 0.06 × 0.04 × 0.015 mm, in the vugs of volcanic scoria, associated with cerussite. In the same scoria where manuelarossiite was found, anglesite, artroeite, atacamite, calcioaravaipaite, cerussite, challacolloite, cotunnite, hephaistosite, matlockite, napoliite and susannite were identified. Manuelarossiite is colourless with a white streak and adamantine lustre. It is brittle and has a laminated fracture. Cleavage is perfect on {001}. Dcalc = 5.095 g cm–3. The calculated mean refractive index is 1.625. The chemical composition (wt.%, electron microprobe, H2O calculated by stoichiometry) is: CaO 13.98, PbO 55.46, Al2O3 12.59, F 29.45, H2O 1.68, –O=F –12.40, total 100.76. The empirical formula calculated on the basis of 7 anions is Ca1.00Pb1.00Al1.00[F6.25(OH)0.75]Σ7.00. Raman spectroscopy confirms the limited presence of OH– groups in the mineral. Manuelarossiite is monoclinic, space group C2/m, with a = 7.6754(3), b = 7.4443(4), c = 9.2870(5) Å, β = 93.928(5)°, V = 529.39(5) Å3 and Z = 4. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 9.257 (57) (001); 4.537 (72) (111); 3.725 (98) (020); 3.630 (57) (20$\bar 1$); 3.588 (65) (11$\bar 2$); 3.460 (100) (021); 3.422 (63) (112); and 2.673 (65) (220). The crystal structure was refined to R1 = 0.056 for 849 reflections with F > 4σ(F). It is characterised by {001} layers formed by CaF8 polyhedra decorated on both sides by AlF6 octahedra, in turn connected to the {001} layer through edge-sharing. Successive {001} layers are bonded through Pb atoms. The new mineral honours Dr. Manuela Rossi (b. 1977) from the University of Naples for her contribution to the study of the Vesuvius volcano and its minerals.

The new mineral pabellóndepicaite (IMA2023-104), Cu2+2(N3C2H2)2(NH3)2(NO3)Cl·2H2O, was found in the guano deposit at Pabellón de Pica, Iquique Province, Chile, where it is a secondary phase formed at the contact between an altered guano deposit and a chalcopyrite-bearing gabbro. Pabellóndepicaite occurs on salammoniac in association with antipinite, bojarite, dittmarite, halite, joanneumite, sampleite, struvite, wheatleyite and whewellite. Crystals are rectangular blades or tablets, up to ∼0.2 mm long, flattened on {001} and elongated along [100] and exhibiting the forms {010}, {001}, {011} and {102}. Crystals are indigo blue and transparent, with vitreous lustre and light indigo blue streak. The mineral is brittle with curved and stepped fracture. The Mohs hardness is ∼2½. Cleavage is perfect on {001} and good on {010}. The density is 1.95(2) g·cm–3. Optically, pabellóndepicaite is biaxial (+) with α = 1.583(3), β = 1.596(3) and γ = 1.644(3) (white light). The 2V is 56(2)° with distinct r > v dispersion. The optical orientation is X = a, Y = b, Z = c and the pleochroism is X light indigo blue, Y indigo blue, Z pale indigo blue; Y > X > Z. The empirical formula is Cu2Cl1.25N9C4H13.75O4.75 (with H, C and N calculated based on the structure). Pabellóndepicaite is orthorhombic, space group Pmma, with cell parameters: a = 7.2118(12), b = 9.0983(15), c = 11.128(3) Å, V = 730.2(2) Å3 and Z = 2. The structure (R1 = 6.65% for 482 I > 2σI reflections) contains two types of polyhedral chains (1) a zig-zag chain of CuN4Cl2 octahedra linked by sharing Cl atoms and the N–N edges of 1,2,4-triazolate groups and (2) a chain of CuN4O2 octahedra alternating with NO3 triangles. The chains are linked to one another by 1,2,4-triazolate groups to form layers with isolated H2O groups in their cavities.

Oral cancer survival rates have seen little improvement over the past few decades. This is mainly due to late detection and a lack of reliable markers to predict disease progression in oral potentially malignant disorders (OPMDs). There is a need for highly specific and sensitive screening tools to enable early detection of malignant transformation. Biochemical alterations to tissues occur as an early response to pathological processes; manifesting as modifications to molecular structure, concentration or conformation. Raman spectroscopy is a powerful analytical technique that can probe these biochemical changes and can be exploited for the generation of novel disease-specific biomarkers. Therefore, Raman spectroscopy has the potential as an adjunct tool that can assist in the early diagnosis of oral cancer and the detection of disease progression in OPMDs. This review describes the use of Raman spectroscopy for the diagnosis of oral cancer and OPMDs based on ex vivo and liquid biopsies as well as in vivo applications that show the potential of this powerful tool to progress from benchtop to chairside.

Fluor-rossmanite, ideally □(Al2Li)Al6(Si6O18)(BO3)3(OH)3F, is a new mineral of the tourmaline supergroup, found at the Krutaya pegmatite, Malkhan pegmatite field, Zabaykalskiy Krai, Western Siberia, Russia. It forms an intermediate zone up to 3 mm thick in a chemically heterogeneous, concentrically zoned, polychrome tourmaline crystal 3 × 2 cm in size. The new mineral is light pink, transparent with a white streak and a vitreous lustre. It is brittle, with conchoidal fracture. The Mohs hardness is 7. The Dmeas = 3.07(2) g cm–3 and Dcalc = 3.071 g cm–3. Optically, fluor-rossmanite is non-pleochroic, uniaxial (–), ω = 1.647(2) and ɛ = 1.628(2) (589 nm). The empirical formula calculated on the basis of 31 anions (O+OH+F) is: X(□0.46Na0.32Ca0.20Pb0.02)Σ1.00 Y(Al1.84Li1.05Mn0.05Fe2+0.02Ti0.02Cr0.01)Σ2.99 ZAl6.00 T(Si5.79Al0.21)Σ6.00B2.99O27 V(OH)3 W[F0.44(OH)0.20O0.36]Σ1.00. Fluor-rossmanite is trigonal, R3m; the unit-cell parameters are: a = 15.7951(3), c = 7.08646(17) Å, V = 1531.11(7) Å3 and Z = 3. The crystal structure is refined from single-crystal X-ray diffraction data [R = 0.0211 for 1178 unique reflections with I > 2σ(I)]. The new mineral is a ‘fluor-’ species belonging to the X-vacant group of the tourmaline supergroup. The closest end-member compositions of valid tourmaline species are those of rossmanite and fluor-elbaite, to which fluor-rossmanite is related by the substitutions WF– ↔ WOH– and X2□ + YAl3+ ↔ X2Na+ + YLi+, respectively.