This new mineral was first found by a miner named Cann in 1903 or 1904 on the 480-foot level of the Bultfontein mine at Kimberley. It occurred, associated with calcite, apophyllite, and natrolite, in a large ‘horse’ of dolerite and shale fragments enclosed in kimberlite. This huge inclusion, several hundred feet in height, undoubtedly formed part of the country-rock that now encloses the kimberlite pipe. The Specimens of the new mineral were considered to be natrolite and were presented to Mr. A. F. Williams. Several years later the same mineral was found by Mr. C. E. Adams in the Dutoitspan mine, which is located about half a mile from the Bultfontein mine; he presented his specimens to the MacGregor Museum at Kimberley. Recently, Mr. Miller, Underground Manager of the Jagersfontein mine in Orange River Colony, discovered the new mineral in that mine, which is located 100 miles south-east of Kimberley.

The present investigation began with an attempt to isolate and analyse the small sparse anorthoclase insets (t)henocrysts) of the chilled glassy selvage of a felsite dike. On comparison of the compositions of the insets and the host rock it was found that the relationship was abnormal and that the insets could not have grown in a magma represented by the glass. The composition of the felsite interior of the dike, however, represents a magma which could have yielded the anorthoclase, and full consideration leads to the conclusion that the glass, though absolutely fresh and unaltered in appearance, has suffered marked changes in composition.

Among a number of specimens which the senior author (J. l)rugman) obtained some years ago from the widow of a mine manager, Mr. Legrand, of Belgian nationality, was one of massive blendc from the Flor de Peña mine, Lampazos, Nuevo Leon, Mexico, which carried a small quantity of a bright yellow, transparent substance that could not be identified with any known mineral. Goniometric and optical examination showed it to be monoclinic, but the material was mainly massive radiating-prismatic, and the few freely developed crystals gave only very approximate measurements (see table II). A chemical analysis by the iunior author showed it to be indeed a new mineral, a basic zinc arsenate, and the name ‘legrandite’ is proposed for it in recognition of the collector. The larger part of what remains after investigation of the small specimen has been presented to the British Museum for preservation in the mineral collection.

A recent account of pseudo-meteorites by Dr. L. J. Spencer includes a description of nodules of pyrite ‘popularly thought to be “thunderbolts”’. Dr. Spencer himself collected in 1931 a large number from the Lower Chalk outcropping on the foreshore below ‘The Warren’ at Folkestone, Kent. Some of these show well-developed octahedra 5 to 10 ram. across on the outer surface, undoubtedly to be referred to pyrite. More commonly the nodules exhibit small distorted octahedra which might easily be mistaken for marcasite. Indeed, in the past, many of these nodules from the Chalk at Folkestone and elsewhere, have been named marcasite, and they were so labelled in the British Museum collection. Dr. Spencer, therefore, suggested that modern methods should be applied to those cases where the crystalline form is distorted or shOt sufficiently developed to serve as a means of distinction between pyrite and marcasite. The methods suggested in his paper are (1) X-rays, (2) polarized light reflected from polished sections of nodules.

Concentrates from the platiniferous norites of the Bushveld, Transvaal, are not completely soluble in aqua regia. The insoluble portion consists of steel-grey fragments first analysed chemically by R. A. Cooper and considered by him to be a new platinum mineral represented by the formula Pt(As,S)2. The name cooperite was proposed for the new mineral by F. Wartenweiller, and after further work Cooper decided that the arsenic found in the early analysis was due to the presence of sperrylite, and he changed the formula to PtS2. H. Schneiderhöhn observed simple twinning and, less frequently, polysynthetie lamellae on polished sections of mineral grains from the same deposits, and he suggested that cooperite is probably orthorhombic and isomorphous with marcasite. The latest account of the new mineral has been published by H. R. Adam who gave several analyses of cooperite from the Rustenburg and Potgietersrust districts and concluded that the ‘mineral is PtS2 with a small amount of excess metal (platinum, palladium, and nickel) present in solid solution’.