Orthopyroxene and clinopyroxene, with biotite, are widespread in the high-level Cheviot granite, while amphibole is rare. The pyroxene compositions are very close to (Mg,Fe)2Si2O6 and Ca(Mg,Fe)Si2O6. Biotite compositions, with low Si and Al, are characteristic of biotites coexisting with pyroxenes. Geothermometric estimates based on oxide and pyroxene compositions show that present mineral compositions result from post-consolidation equilibration.

A very interesting kornerupine-bearing rock was sent by Mr. W. H. Cross during 1938 to the Geological Survey for identification. The material, of which about 800 grams were available for study, was stated to have been found in the Port Shepstone district. The occurrence has, however, not been visited by the writer.

The hand-specimens examined were all somewhat weathered. Macroscopically these consisted of an intergrowth of grey, columnar crystals of kornerupine, up to 5 centimetres in length, and adhering iron-stained quartz. Shiny ‘books’ of biotite occur both in the kornerupine and the quartz, while small patches and specks of dark brown tourmaline and bluish grandidierite were observed enclosed in the kornerupine.

The references to the occurrence of the titanium dioxide minerals as rock constituents have been so recently summarized in the ‘Mineralogical Magazine, that it is unnecessary to repeat them, except to refer again to Mr. J. J. H. Teall's record of anatase in the Cleveland ironstone.

Wishing to procure some of these crystals, a pound of ore from the Main Seam at Upleatham mines was treated by the usual processes of solution, washing by decantation, and separation by heavy solution. The residue obtained was equal to 0.16 per cent. of the material taken, and consisted mainly of anatase, mostly in sharply developed pyramidal crystals, with some pyrites in nodular concretions, possibly in replacement of some of the oolitic grains, together with other minerals of derived origin, among which futile and tourmaline were the most prominent.

Marshallsussmanite (IMA2013-067) is a new pyroxenoid mineral from the Wessels mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Marshallsussmanite has ideal formula NaCaMnSi3O8(OH) and triclinic P$\bar{1}$ symmetry. Marshallsussmanite forms vitreous pink bladed crystals to 2.1 cm. The mineral shows perfect cleavage on both {100} and {001}. The chemical composition from electron microprobe (average of 20 analyses) and inductively coupled plasma mass spectrometer analysis (average of three analyses) is Li2O 0.43, Na2O 8.06, MgO 0.08, CaO 15.33, MnO 21.79, SiO2 51.71; totalling 97.40 wt.%. The empirical formula, normalized to 3 Si and assuming 1 H apfu is Li0.100Na0.906Ca0.953Mg0.007Mn1.071Si3O8(OH). Unit-cell parameters from single crystal X-ray diffraction are a = 7.7854(4), b = 6.9374(4), c = 6.8516(3) Å, α = 90.683(3)°, β = 94.330(3)°, γ = 102.856(3)°, V = 359.59(3) Å3; Z = 2. The crystal structure refinement converged with Robs = 0.0248 and site occupancy refinement gives crystal chemistry [Na0.948Li0.052][Ca0.793Mn0.207] [Mn0.937Ca0.063]Si3O8(OH). Marshallsussmanite is a single chain silicate with a repeat interval of three tetrahedra (i.e. dreier chain). Marshallsussmanite is a member of the pectolite group of pyroxenoids, which also includes barrydawsonite-(Y), cascandite, pectolite, serandite and tanohataite. Parallel silicate chains form layers, intercalated with well-ordered cation layers. Calcium and Mn both exhibit octahedral coordination, while Na has four bonded interactions in a coordination sphere (radius 3 Å) of seven separate O atoms. Procrystal electron density and bond valence modelling results are compared. The mineral has an unusually strong hydrogen bond with O4⋅⋅⋅O3 separation of 2.458(2) Å. Unlike pectolite and serandite, O4 in marshallsussmanite acts as an H-bond donor and O3 is an H-bond acceptor. Cation ordering in pyroxenoids has a substantial impact on the H position and corresponding H-bonding schemata.

The Boxhole meteorite crater has been described previously. It is in Central Australia at latitude 22° 37′ 30´″ S., longitude 135° 11′ 59″ E. During the single afternoon that was spent examining this great crater, nearly 200 yards across, most of the time was occupied with taking measurements and photographs, and only a few shale-balls were found in the way of meteoritic material. Mr. Joe Webb, who lives nearby, was instructed to continue the search, and in due course he sent down to Adelaide three pieces of iron weighing respectively 17 lb. 9 oz., 1 lb. 8 oz., and 5 oz., shown in figs. 1 and 3, together with six more shale-balls. This material was purchased by the South Australian Museum. Two other small pieces of iron have been obtained by the author from other sources.

In a recent paper by Dr. W. F. Fleet and Dr. F. Smithson attention was drawn, to the occurrence of dark apatites and apatitcs with dark cores of inclusions in certain sediments of the Midlands of England, and it was pointed out that the only other definite occurrences known of these peculiar apatite grains in either igneous or sedimentary rocks appeared to be restricted to the Old Red Sandstone of the Cardiff area, the ‘newer’ granites of Jersey, and the Leinster granite. These writers also expressed the hope ‘that any future observation of such grains may be recorded with a view to tracing the source of the detrital grains of Welsh and English rocks’.

Kihlmanite-(Ce), Ce2TiO2[SiO4](HCO3)2(H2O), is a new rare-earth titanosilicate carbonate, closely related to tundrite-(Ce). It is triclinic, P, a = 4.994(2), b = 7.54(2), c = 15.48(4) Å, α = 103.5(4), β = 90.7(2), γ = 109.2(2)o , V = 533(1) Å3, Z = 2 (from powder diffraction data) or a = 5.009(5), b = 7.533(5), c = 15.407(5) Å, α = 103.061(5), β = 91.006(5), γ = 109.285(5)°, V = 531.8(7) Å3, Z = 2 (from single-crystal X-ray diffraction data). The mineral was found in the arfvedsonite-aegirine-microcline vein in fenitized metavolcanic rock at the foot of the Mt Kihlman (Chil’man), near the western contact of the Devonian Khibiny alkaline massif and the Proterozoic Imandra-Varzuga greenstone belt. It forms brown spherulites (up to 2 cm diameter) and sheaf-like aggregates of prismatic crystals, flattened on {010} and up to 0.5 mm diameter. Both spherulites and aggregates occur in interstices in arfvedsonite and microcline, in intimate association with golden-green tundrite-(Ce). Kihlmanite-(Ce) is brown, with a vitreous lustre and a pale yellowish-brown streak. The cleavage is perfect on {010}, parting is perpendicular to c and the fracture is stepped. Mohs hardness is ∼3. In transmitted light, the mineral is yellowish brown; pleochroism and dispersion were not observed. Kihlmanite-(Ce) is biaxial (+), α = 1.708(5), β = 1.76(1), γ = 1.82(1) (589 nm), 2Vcalc = 89°. The optical orientation is Y ^ c = 5°, other details are unclear. The calculated and measured densities are 3.694 and 3.66(2) g cm−3, respectively. The mean chemical composition, determined by electron microprobe, is: Na2O 0.13, Al2O3 0.24, SiO2 9.91, CaO 1.50, TiO2 11.04, MnO 0.26, Fe2O3 0.05, Nb2O5 2.79, La2O3 12.95, Ce2O3 27.33, Pr2O3 2.45, Nd2O3 8.12, Sm2O3 1.67, Gd2O3 0.49 wt.%, with CO2 15.0 and H2O 6.0 wt.% (determined by wet chemical and Penfield methods, respectively), giving a total of 99.93 wt.%. The empirical formula calculated on the basis of Si + Al = 1 atom per formula unit is (Ca0.16Na0.11Mn0.02)∑0.29[(Ce0.98La0.47Pr0.09Nd0.29Sm0.06Gd0.02)∑1.91(Ti0.82Nb0.12)∑0.94O2 (Si0.97Al0.03)∑1O4.02(HCO3)2.01](H2O)0.96. The simplified formula is Ce2TiO2(SiO4)(HCO3)2·H2O. The mineral reacts slowly in cold 10% HCl with weak effervescence and fragmentation into separate plates. The strongest X-ray powder-diffraction lines [listed as d in Å(I) (hkl)] are as follows: 15.11(100)(00), 7.508(20)(00), 6.912(12)(01), 4.993(14)(00), 3.563(15)(01), 2.896(15)(1). The crystal structure of kihlmanite-(Ce) was refined to R1 = 0.069 on the basis of 2441 unique observed reflections (MoKα, 293 K). It is closely related to the crystal structure of tundrite-(Ce) and is based upon [Ce2TiO2(SiO4)(HCO3)2] layers parallel to (001). Kihlmanite-(Ce) can be considered as a cationdeficient analogue of tundrite-(Ce). The mineral is named in honour of Alfred Oswald Kihlman (1858–1938), a remarkable Finnish geographer and botanist who participated in the Wilhelm Ramsay expeditions to the Khibiny Mountains in 1891–1892. The mineral name also reflects its occurrence at the Kihlman (Chil’man) Mountain.

In X-ray studies of fireclays we have frequently observed the presence of anatase to the extent of 1 or 2% with little or no rutile, and no brookite. Chemical analyses of these clays usually record 1–2% of TiO2 and occasionally more (Ennos and Scott, 1924). The mineralogical form of the TiO2 is usually not stated, but a number of references to the observance of rutile needles give the impression that rutile is the form in which titania occurs in these deposits. Our own observations based on X-ray powder photographs lead us to conclude that anatase is commonly present and that rutile is either absent or present in smaller quantities. We have not detected brookite.

Some small isolated crystals from the gem-washings in Ceylon, recently sent by Mr. A. K. Coomáraswámy to the British Museum for determination and study, were at first thought to be rutile, but on detailed examination proved to be zircon of a rather unusual type. This has a specific gravity of 4.0, which is not increased when the crystals are heated.

The majority of the crystals are from the Balangoda district in the Sabaragamuwa province, and, according to Mr. Coomáraswámy have been derived from a group of zircon-granites which occur in this district; a few others are from Walaweduwa in the Bamberabotnwa district, and from the Hatton district. Associated with them are zircons of more usual types (see p. 48); the present description is, however, confined to the crystals of lower specific gravity.

An unusual highly hydrated and Na-depleted variety of elpidite was identified in a hydrothermally altered peralkaline pegmatite at Mt. Yukspor in the Khibiny alkaline complex, Kola Peninsula, Russia. It differs from ‘ordinary’ elpidite, ideally Na2ZrSi6O15⋅3H2O, in its crystal chemical features, infrared spectrum and optical characteristics. The chemical composition (wt.%, electron microprobe, H2O by TGA) is: Na2O 5.45, K2O 0.67, CaO 0.05, SiO2 60.32, TiO2 1.34, ZrO2 18.43, Nb2O5 0.65, H2O 12.80, total 99.71. The empirical formula calculated on the basis of 6 Si and 15 O atoms is [(Na1.05K0.08Ca0.01)Σ1.14(H3O)0.74]Σ1.88(Zr0.89Ti0.10Nb0.03)Σ1.02Si6O15⋅3.47H2O; the H2O:H3O ratio was calculated from the charge balance requirement, taking into account the results of crystal structure refinement. The highly hydrated variety of elpidite is orthorhombic, Pma2, a = 14.5916(6), b = 7.3294(3), c = 7.1387(2) Å, V = 763.47(5) Å3 and Z = 2. The crystal structure was solved from single-crystal X-ray diffraction data, R1 = 3.43%. The structure is based upon an elpidite-type heteropolyhedral Zr–Si–O framework with Na+ and H3O+ cations and H2O molecules in the zeolitic channels. Hydronium cations substitute for water molecules in one of the extra-framework sites. This variety of elpidite could be considered as an intermediate product of natural ion-exchange reaction between ‘ordinary’ elpidite and a low-temperature hydrothermal fluid.

Quartz from a granite pegmatite near Kalkovo, Bulgaria, has undergone partial replacement by biotite along cracks parallel to (01;0); the biotite is in regular orientation relative to the quartz, and appears to constitute an instance of epitaxic replacement, defined as a replacement in which the replacing mineral develops in a regular, structurally controlled orientation relative to the mineral replaced.

Dana classifies gümbelite in the kaolin division under pyrophyllite, and expresses the view that it may be an impure pyrophyllite. The present study, however, has shown that the unit cell of gümbelite is very similar to that of muscovite. Also the chemical analysis reveals a Closer similarity to muscovite, particularly to a variety called hydromuscovite.

Baumoite, Ba0.5[(UO2)3O8Mo2(OH)3](H2O)~3, is a new mineral found near Radium Hill, South Australia, where it occurs in a granite matrix associated with baryte, metatorbernite, phurcalite and kaolinite. Baumoite forms thin crusts of yellow to orange–yellow tabular to prismatic crystals. The mineral is translucent with a vitreous lustre and pale yellow streak. Crystals are brittle, the fracture is uneven and show one excellent cleavage. The Mohs hardness is ~2½. The calculated density is 4.61 g/cm3. Optically, baumoite crystals are biaxial (–), with α = 1.716(4), β = 1.761(4), γ = 1.767(4) (white light); and 2Vcalc = 42.2°. Electron microprobe analyses gave the empirical formula Ba0.87Ca0.03Al0.04U2.97Mo2.02P0.03O22H11.99, based on 22 O atoms per formula unit. The eight strongest lines in the powder X-ray diffraction pattern are [dobs Å (I) (hkl)]: 9.175(39)(12${\bar 1}$), 7.450(100)(020), 3.554(20)(221), 3.365(31)(004, 202), 3.255(31)(123, 30${\bar 2}$), 3.209(28)(12${\bar 4}$), 3.067(33)(30${\bar 3}$, 222, 32${\bar 2}$) and 2.977(20)(142). Single-crystal X-ray studies (R1 = 5.85% for 1892 main reflections) indicate that baumoite is monoclinic, superspace group X2/m(a0g)0s with X = (0,½,0,½), with unit-cell parameters: a = 9.8337(3), b = 15.0436(5), c = 14.2055(6) Å, β = 108.978(3)°, V = 1987.25(13) Å3 and Z = 4. The crystal structure is twinned and incommensurately modulated and is based upon sheets of U6+ and Mo6+ polyhedra of unique topology. Four independent cationic sites partially occupied by Ba atoms are located between the sheets, together with H2O molecules.

The associations hornblende and anthophyllite or cummingtonite are dealt with briefly in the light of experimental data and naturally occurring assemblages. On the basis of the distribution of Mg and Fe2+ in coexisting amphiboles and on the calculated and experimental slopes of a reaction in which the amphiboles hornblende and anthophyllite are formed a tentative P-T-x diagram is suggested for these parageneses.

The type specimen of peisleyite has been reinvestigated by a combination of scanning electron microscopy, electron probe microanalysis (EPMA) and synchrotron powder X-ray diffraction. Morphological investigation showed that mats of peisleyite crystals, individually <3 μm across, are intergrown with wavellite veinlets to form the white cryptocrystalline material that is typical of ‘peisleyite’. New EPMA data (mean of 12 analyses) gave the empirical formula of peisleyite as (Na1.69Ca0.18)Σ1.87(Al9.04Fe0.03)Σ9.07[(P6.28S1.38Si0.25)O4]Σ7.91(OH)6.66·27.73H2O, or ideally Na2Al9[(P,S)O4]8(OH)6·28H2O. The associated wavellite was found to be F-rich. Synchrotron powder data were indexed and refined and gave the following unit cell: P1̄, a = 9.280(19), b = 11.976(19), c = 13.250(18) Å, α = 91.3(1), β = 75.6(1), γ = 67.67(1)°, V = 1308(5) Å3 and Z = 4. These data are significantly different to those reported in the original description of peisleyite.

By the publication of his paper on 'The source of the purple zircons in the sedimentary rocks of Scotland', Dr. Wm. Mackie has done his fellow-workers on the petrology of British sedimentary rocks a signal service, He has proved that this distinctive purple (or sometimes rosecoloured) variety of zircon is relatively abundant in the Lewisian gneiss. The variety occurs usually as rounded or ovoid grains, but occasionally with crystalline form ; it is often finely polished, as if by wind, and is sometimes zoned, with a darker centre, or displays colour of varying intensity; it is often definitely, although but slightly, pleochroic, and usually possesses high bireffingence. These characteristics at once bring to mind grains of zircon frequently met with in sedimentary rocks and recorded by numerous other observers.