A new British locality for beudantite [PbFe3(AsO4)(SO4)(OH)6] is recorded. The mineral is intimately associated with goethite; chemical, d.t.a., and thermogravimetric analysis data for the mixture are presented and a possible paragenesis suggested.

Simple laboratory experiments involving the contact of distilled water with crushed olivine-basalt over several months under atmospheric temperature and pressure conditions have shown that constituents are dissolved from the basalt and upon evaporation the solutions deposit crystals of carbonates, smectites, and zeolites. The results bear out the observations and conclusions previously made in the field that solutions depositing secondary minerals in Tertiary basalts in New South Wales are extraneous and cold. It is also suggested that as the assemblage calcite-montmorillonite-heulandite can form in the vesicles of basalts under such conditions it should not be included in the zeolite facies of metamorphism.

A rock from the Mt. Painter area, South Australia, consists essentially of corundophilite (anal., X-ray) and corundum, with accessory boehmite, sapphirine, cordierite, muscovite, and rutile. The rock probably crystallized at 500 to 700°C under 20 000 Ib/in.2 pressure, boehmite being formed by retrogressive metamorphism at 120 to 280° C.

Extinction readings are taken, on a polarizing microscope, for several wave-fronts in a biaxial crystal (more than four wave-fronts are required). With these extinction data, the machine then calculates the directions of the two optic axes and of the three principal axes of the indicatrix, as well as the value of the optic axial angle 2V, using a least-squares successive approximation technique. The programme was written for an IBM 1620 computer.

A spherulitic mineral occurring as veins and nodules in celestine-bearing secondary limestones in the Lower Purbeck Beds at Durlston Head, Swanage, Dorset, is identified as calciostrontianite, a mineralnot previously recorded from Britain. Textural relationships indicate that it was formed from the alteration of celestine and was in part converted back into celestine. The calciostrontianite originated as an epigenetic mineral during the tectonic movement that gave rise to the Broken Beds.

An improved water cell for the Universal Stage is described for use in the Emmons double-variation procedure. The cell provides an increased heat flow to the mineral grains, and the technique of orientating and retaining the grains in the centre of the field of view is greatly simplified.

The characteristics of a phlogopite and its weathering product, vermiculite, have been studied by X-ray, infra-red, electron-microscope, and chemical methods. Inclusions within these minerals have been identified as thin films rich in iron oxide (which impart a schiller effect), spinel (which may exist in a preferred orientation), and serpentine. The orientation relationship between the fresh mica and its weathering product has been established by single-crystal methods. The mechanism of transformation from a 1-layer to a 2-layer polytype is discussed.