The andesine-dolerite of Squilver Hill, situated nearly 3 miles due north of Bishops Castle, has been described in another place. This somewhat coarse-textured rock, with a distinctive greenish-blue colour, contains up to 20 per cent. of a fresh monoclinic pyroxene as crystals of irregular shape, many of which are about a millimetre in length. The rest of the rock consists of saussuritized plagioclase, some interstitial chlorite and prehnite, and accessory apatite, sphene, magnetite, and ilmenite; the unaltered nature of the pyroxene is noteworthy.

Lyndochite from Tura dukas, 35 miles north of Nanyuki, Kenya, agrees closely with the type material from Canada in its chemical analysis, in the distribution of the rare earths, and in X-ray diffraction data for powder after heat treatment. The mineral is compared and contrasted with aeschynite. Uranium-poor euxenite is intimately associated with lyndochite at the type locality.

Since its discovery over thirty-five years ago, lyndochite has remained unrecorded outside its type locality of Lyndoch Township in Ontario, Canada. Its distinctive chemical composition sets it apart from almost all other Ti-rich metamiet niobates and, despite the many analyses that have been made on rare-earth niobate-tantalates, specimens that could have been regarded as similar to or approximating to lyndochite have rarely been mentioned. Its unusual characteristics include high ThO2 (about 10%) and appreciable rare-earth oxides (about 20%) with a lanthanon assemblage showing a peak concentration of Nd (and Ce), rather than any of the heavy lanthanons. The proportions of TiO2 (about 20%) and (Nb,Ta)2O5 (about 40%) are comparable to those in numerous niobate-tantalates, but are only associated with the percentages of ThO2 and Re2O3 mentioned above in some members of the aesehynite-priorite series. The lyndochite now described is chemically very close indeed to the Canadian lyndochite, and both specimens give closely similar X-ray diffraction patterns (after suitable heat treatment) which are distinct from those of any other metamict mineral.

A small specimen (McGregor Museum, no. 4465) labelled ' Bismuth ore' was sent to me in 1932 by Miss M. Wilman, Curator of the McGregor Museum, Kimberley, for identification. It had been presented to the Museum by Mr. M. Caplan, a store-keeper of Steinkopf. The majority of bismuth-bearing minerals from Namaqualand come from a number of spots in the neighbourhood of the water-hole known as Jackals Water, which is situated 18 miles NNE. of the village of Steinkopf. Reference has already been made to this locality in a previous paper. The exact locality of this specimen is a pegmatite outcrop in granite-gneiss about a mile and a half south of the Noumaas trigonometrical beacon which is situated some 13 miles north-west of Jackals Water to the west of the Viool's Drift road. The specimen was picked up on the surface, being obviously of eluvial origin.

Whole-rock, minor element, rare earth, and electron microprobe data are presented for basaltic lavas from the western Kangerdlugssuaq area of East Greenland. Samples were obtained from Professor W. A. Deer's 1936 collection at Triangular Nunataks and Gardiner Plateau, and additional material obtained by sampling moraines on the surface of Kangerdlugssuaq Glacier. Both undersaturated and tholeiitic lavas are present at the Triangular Nunatak locality but the glacier suite is dominantly tholeiitic. The tholeiitic suite is less evolved than tholeiites from the Scoresby Sund area. Undersaturated lavas show enrichment in light rare earth elements and tholeiitic lavas show fiat chondrite-normalized patterns. Tholeiites from the Gardiner Plateau show no Eu anomaly but others show a slight negative Eu anomaly. Chemical data and considerations of regional geology are consistent with Cox's (1980) model of flood basalt vulcanism.

New occurrences of derbylite, Fex2+Fe3+4–2xTi4+3+xSb3+O13(OH), and graeserite, Fex2+Fe3+4–2xTi4+3+xAs3+O13(OH), have been identified in the Monte Arsiccio mine, Apuan Alps, Tuscany, Italy. Derbylite occurs as prismatic to acicular black crystals in carbonate veins. Iron and Ti are replaced by V (up to 0.29 atoms per formula unit, apfu) and minor Cr (up to 0.04 apfu). Mössbauer spectroscopy confirmed the occurrence of Fe2+ (up to 0.73 apfu), along with Fe3+. The Sb/(As+Sb) atomic ratio ranges between 0.73 and 0.82. Minor Ba and Pb (up to 0.04 apfu) substitute. Derbylite is monoclinic, space group P21/m, with unit-cell parameters a = 7.1690(3), b = 14.3515(7), c = 4.9867(2) Å, β = 104.820(3)° and V = 495.99(4) Å3. The crystal structure was refined to R1 = 0.0352 for 1955 reflections with Fo > 4σ(Fo). Graeserite occurs as prismatic to tabular black crystals, usually twinned, in carbonate veins or as porphyroblasts in schist. Graeserite in the first kind of assemblage is V rich (up to 0.66 apfu), and V poor in the second kind (0.03 apfu). Along with minor Cr (up to 0.06 apfu), this element replaces Fe and Ti. The occurrence of Fe2+ (up to 0.68 apfu) is confirmed by Mössbauer spectroscopy. Arsenic is dominant over Sb and detectable amounts of Ba and Pb have been measured (up to 0.27 apfu). Graeserite is monoclinic, space group C2/m, with unit-cell parameters for two samples: a = 5.0225(7), b = 14.3114(18), c = 7.1743(9) Å, β = 104.878(3)°, V = 498.39(11) Å3; and a = 5.0275(4), b = 14.2668(11), c = 7.1663(5) Å, β = 105.123(4)° and V = 496.21(7) Å3. The crystal structures were refined to R1 = 0.0399 and 0.0237 for 428 and 1081 reflections with Fo > 4σ(Fo), respectively. Derbylite and graeserite are homeotypic. They share the same tunnel structure, characterised by an octahedral framework and cuboctahedral cavities, hosting (As/Sb)O3 groups and (Ba/Pb) atoms.

Finely laminated (cm–μm scale) metalliferous precipitates are widespread in the surficial environment, especially around mineral deposits and reflect biogeochemical processes that can pervade near-surface environments on a larger scale. Examples in this paper involve precipitates of the transition metals Fe, Cu and Mn with minor Co, Ni, V and Zn; the metalloids As and Sb; and authigenic Au. Mobility and re-precipitation are driven primarily by geochemical disequilibrium, especially with respect to pH and redox states, that arises from complex interactions between biological processes, geological processes, and variations in the surrounding environment. Different degrees of chemical disequilibrium arise on small spatial scales on time scales of days to millennia. Interactions between biota, waters and rocks in these small near-surface settings affect the biogeochemical environments. Sulfur- and iron-oxidising bacteria are common biogeochemical agents associated with sulfide-bearing lithologies, but localised reductive environments can also develop, leading to gradients in pH and redox state and differential metal mobility. In general, there is commonly a spatial separation of Fe-rich precipitates from those with Cu and Mn, and other transition metals also follow Cu and Mn rather than Fe. Metalloids As and Sb have a strong affinity for Fe under oxidising conditions, but not under more reducing conditions. However, complex biogeochemical parageneses of laminated metalliferous deposits preclude prediction of finer formation details. The textures, mineral species, and metal associations within these deposits are likely to be encountered in all facets of mineral deposit development: initial exploration activity of near-surface locations, mining of shallow portions of orebodies, especially supergene zones, and downstream environmental management with respect to discharging metalliferous waters.

A number of secondary minerals have grown in recent years in a part of the Billingham anhydrite mine, by evaporation of water from the Upper Magnesian Limestone, and include some unusual species, the most interesting of which is thought to be ilsemannite.

It was with considerable reluctance that I felt myself compelled to discard the system of coloration adopted in the Geological Survey Maps; and rids I did only after the strongly expressed opinion of several geologists.

It was not that I have any very intense desire to colour rocks after their natural tints, but I have an aversion to adopting a colour suite which departs markedly therefrom; or one which is in discordance instead of harmony therewith. One friend, a man of great scientific discretion, and himself an artist, writes me that when he looks at a recently published geological Map of Scotland, with its grey Torridon and its red Laurentian, he does not know whether he is standing on his head or his heels.

The geological set-up, chemical composition, physical and optical properties, and X-ray data of one sample of chrome-chlorite (kämmererite) and of a chrome-garnet (uvarovite) from Kalrangi chromite mines, Orissa, India, are presented here. Chrome-bearing solution contributed in the formation of both the minerals in the hydrothermal stage. It is suggested that the garnet is an intermediary form between uvarovite and pyrope.

The accurate analysis of an igneous silicate rock is a task beset with difficulties and one which, on account of the very complete analyses now required by petrologists, involves the expenditure of a considerable amount of time. The advantages which accrue from the performance of quantitative analytical operations on the micro-scale are becoming more and more apparent, and the application of at least semi-micro-analytical methods to rocks was thought to have profitable possibilities, particularly in the way of hastening the analyses.

The range of temperature within which tourmaline can arise in nature has not hitherto been determined. No synthesis of this mineral is on record, and experimental data are therefore lacking. On the other hand, rutile, brookite, and anatase have all been prepared synthetically, and the experimental data suggest their rutile is formed at the highest temperatures, brookite at temperatures considerably lower, and anatase at a point still lower on the scale. It is generally conceded that for rutile a pyrogenic origin is possible, and that brookite and anatase appear only as secondary minerals. The status of tourmaline as a possible pyrogenic mineral is regarded as doubtful by Clarke, who states that' in igneous rocks tourmaline seems to have been produced by fumarole action, and not as a direct separation from the magma'.

Bassetite and uranospathite Were described as new uranium minerals from Cornwall in 1915 by A. F. Hallimond, to whose paper reference should be made to supplement the descriptions given here. The position of both minerals as relatives of autunite was recognized by Hallimond. Unfortunately, chemical analyses could not be obtained and the composition of these minerals has remained uncertain. No further information has been published about uranospathite. In 1940 Meixner reported that microchemical tests of an apparently authentic specimen of bassetite from Cornwall indicated that the mineral was a hydrated iron uranyl phosphate.

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.

Until quite recently, in spite of its characteristic features, andalusite had not been met with in the younger detrital rocks of Britain ; a few years ago, however, I remarked on its relative abundance in the older Pliocene sands of St. Erth and St. Agnes in the west of Cornwall. Its presence in these deposits, in which it is associated with pink garnet and cyanite, is easily explained by the close proximity of the areas of deposition to the metamorphic aureoles of the west of England granitemasses, in which andalusite of identical character is exceedingly common. It also occurs in fair quantity in the Pliocene sands of Lenham in Kent accompanied by cyanite, and together with cyanite and garnet in the Red and Norwich Crags and the Chillesford Beds in the east of England.