A new hydrated aluminium phosphate mineral, kingite, from phosphate workings near Robertstown, South Australia, has an idealized formula Al2O3.Al(OH)3.P2O5.9H2O, with some replacement of OH by F. The specific gravity is 2·2 to 2·3, refractive index 1·514, and percentage chemical composition Al2O3 31·92, P2O5 28·63, H2O 37·93. The three strongest lines on the X-ray diffraction pattern are 9·1, 3·45, and 3·48 Å. Kingite changes to a less hydrated phase between 154° C. and 163° C., which is also considered to be a new aluminium phosphate (meta-kingite) with idealized formula Al2O3.Al(OH)3.P2O5.4H2O. The strongest lines of its X-ray diffraction pattern are at 7·4, 5·02, and 37·19 Å.

A nephelinite from the extinct volcano Mt. Shaberu, North Kivu, Belgian Congo, contains two new minerals: Götzenite is triclinic with a 10·93, b 7·32, c 5·74 Å, α 90°, β 100°, γ 120°; the unit-cell contents approximate to (Ca,Na,Al)7 (Si,Ti)5O15F3·5, and the optical constants are α 1·660, β 1·662, γ 1·670, 2Vγ 52°; sp.gr. 3·138. Götzenite is related to the rinkite series, and, less closely, to wollastonite and pectolite. Combeite is rhombohedral, space-group R3m, R32, or R¯3m, a 10·43, c 13·14 Å., the unit cell containing approximately 3[Na4(Ca,Al,Fe)3Si6O15(O,OH,F)2]; optically uniaxial positive, ε = ω = 1·598±0·002; sp.gr. 2·844.

The formation of columbite has been observed in two carbonatites in south-west Tanganyika where it is due to autometasomatism following the emplacement of the bodies. Disoriented aggregates of columbite crystallites are formed as pseudomorphs after eubo-octahedra of pyrochlore in sövite. This alteration is accompanied by the addition of Fe, conversion of amphibole and biotite in the sövite to a ferruginous tale. the formation of an iron-bearing carbonate, and the introduction of colloform silica: Ca and Na are lost in part. The general alteration of the sövite can be ascribed to the influx of iron-bearing solutions at relatively low temperature and high pressure.

A small specimen at first thought to be natrolite has proved to be a new mineral, for which the name rhodesite is proposed; it is fibrous, with α 1·502, β 1·506, γ 1·515, elongation γ, extinction straight, sp. gr. 2·36. The composition is near 4(Ca,Na2,K2)O. 10SiO2. 7H2O, and the water is all zeolitic.

A study of phase equilibria among the orthosilicates on the Ca2SiO4—CaMgSiO4 join was undertaken with the use of hydrothermal techniques in the temperature range 600–900°C. at water pressures from 1000 to 15000 psi. Monticellite, merwinite, and Ca2SiO4 crystallize as pure phases throughout this temperature range, and intermediate compositions contain mixtures of the end members. Powder X-ray diffraction data obtained on the mixtures indicate no change in lattice dimensions from the end members. Hence, very little or no solid solution is indicated at these temperatures. Ca2SiO4 was crystallized as the γ-form below 675°C. (at 2000 psi) and the β-form above this temperature (presumably having inverted from the α′-form on cooling to room temperature). Infra-red absorption spectra obtained on the compounds γ-Ca2SiO4, β-Ca2SiO4, merwinite, and monticellite show characteristic differences in the pattern within the 9–13 micron region. All the data thus appear to confirm merwinite as a unique compound stable in the temperature range studied.

A manganese pan near Birness contains grains of an optically uniaxial negative mineral near (Na0·7Ca0·3)Mn7O14·2·8H2O, giving an X-ray powder pattern similar to that of synthetic materials described as ‘manganous manganite’ and δ-MnO2. Material giving a similar pattern has been described from a natural occurrence in Canada, but no mineral name was assigned; the name birnessite is now proposed. The mineral is probably formed by air-oxidation of manganous oxides under alkaline conditions.

Descriptions, with chemicaland mineralogical data, are given of zoned wollastonite-grossular-clinozoisite skarns found at the contact of limestone and granite at Puyvalador, near Quérigut, France. It is shown that the silica and alumina necessary for the formation of the skarn were supplied by the adjacent granite, which in return received lime from the marble replaced by the skarn zones. The modified facies of the granite in contact with the skarn is also described; it shows evidence of migration of silica towards the contact and of accumulation of lime derived from the neighbouring marble.

Similar, but not identical, changes are found at other localities along the Quérigut granite contact with limestone. The features of the Puyvalador granite-limestone contacts are compared and contrasted with those described from some other regions. The contact rocks dealt with here are characterized by the presence of abundant clinozoisite, indicative of relatively low temperatures and abundance of water at the contact in the later stages of evolution of the granite.

Four new occurrences of vanadium minerals are described. New X-ray powder data are given for descloizite and mottramite, and show appreciable differences. Evidence is brought that the original occurrence of mottramite was not at Mottram St. Andrew, Cheshire, but Pim Hill, Shropshire, and that most if not all specimens labelled Mottram St. Andrew or Cheshire really came from Pim Hill.

The normal-pattern finder is a mechanical aid for use in finding the various possible configurations of a construction in the Barker system for anorthie crystals. Its purpose is to avoid the drawing of zones in pencil on the stereographic projection, which zones make it more difficult to recognize other differently constructed normal-patterns.

An analysed magnetite from Bisperg, Säter, Dalecarlia, Sweden, gave the formula , which corresponds closely to the ideal composition. A precise determination of the cell dimensions gave a 8·3963±0·0005 Å. at 18° C. Gentle heating of the powdered magnetite in evacuated silica glass tubes, before X-ray examination, resulted in sharply defined lines with high Bragg angles; an improvement which enabled precision data to be obtained. Four other new analyses of magnetites are also given and their lattice parameters are determined in the same way and are found to range from 8·3960 Å. to 8·3970 Å. The Bisperg magnetite being the purest sample examined, the value of its cell edge is taken as representative of pure magnetite.

The effect of the different ionic substitutions on the cell dimensions of natural magnetites is discussed. An attempt is also made to explain the great variations among the published values of cell dimensions of artificial preparations; one main reason being the presence of defect structures with varying oxygen contents in excess of the formula requirements.

A new analysis gives the formula Ca4Si3O12F2H6; the specimen was from Alter Berg, Leitmeritz, Bohemia, and also contained apophyllite. The unit cell is triclinic, but all reflections can be indexed on a geometrically monoclinic cell which is c-face centred and has a 16·2, b 9·34, c 13·2 Å., β 113°, Z = 6, principal cleavage (001). This cell could also be described as having a hexagonal base of side 9·34 Å., but with c tilted through 23° from the vertical in the plane of one of the sides. A dehydration curve showed a step at 300–400°C., corresponding to loss of two-thirds of the water. The remaining water is lost between 400° and 940° C., together with some fluorine, the latter probably as HF. Crystals heated at 450–600° C. retain the hexagonal-based cell, but d001 shrinks from 12·1 to 11·1 Å, and there is evidence of much stacking disorder of layers normal to c. Single crystals heated at 700° C. show ordered transformation, giving cuspidine twinned in three orientations as the only recognizable product. At 940°C. a mixture is obtained, mainly β-CaSiO3 with some β-Ca2SiO4.

In quartz-seheelite veins traversing rocks from the metamorphic complex in the Central Rhodopian mountains, a mineral was found closely resembling bismuthinite. Its composition is Bi 66·62 %, Pb15·50 %, Cu 0·85 %, and S 16·71 %, corresponding to the formula PbBi4S7. It is orthorhombic, long prismatic to acicular with an axial ratio a:b:c = 0·9004:1:0·3249. Observed forms: {110}, {100}, {010}, and {011}. Sp. gr. 6·92. Hardness about 2 1/2. Displays a perfect cleavage along {100}. It is distinctly anisotropic. Strongest X-ray intensities: 3·50 Å. (10), 3·08 (8), 1·939 (8), 2·78 (6), 1·733 (6), 2·50 (5). The name is after the eminent Bulgarian mineralogist and petrographer G. Bonchev.

New chemical, optical, and X-ray data have been obtained for dumortierite. The unit cell. space group Pemn, contains 4[(Al,Fe)7BSi3O18]. Brown gem quality material from Ceylon has α 1·6860, black, [001], β 1·722, deep redbrown, and γ, 1·7229, brown, with 2Vα 13° , γ > υ. X-ray powder data are given.

Rhodesite, from Kimberley, S. Africa, has been examined by electron-microscope, X-ray, and other methods. The acicular crystals are orthorhombic, with a 23·8, b 6·54, c 7·05 Å.; elongation c, cleavage (100); unit-cell contents approximately (Ca,Na2,K2)8Si16O40.11H2O; optical properties α 1·502, β 1·505, γ 1·515; α = b, β = α, γ = c. With it occurs a similar but distinct fibrous mineral, which appears to be a new species for which the name mountainite is proposed; it is monoclinic, with a 13·51, b 13·10, c 13·51 Å., β 104° elongation b, cleavage (001); unit-cell contents approximately (Ca,Na2,K2)16Si32O80.24H2O; optical properties α 1·504, β 1·510, γ 1·519; β = b (elongation). Both rhodesite and mountainite show close similarities to the fibrous zeolites, mountainite in particular resembling thomsonite. The possible structural basis of these similarities is discussed.