When some publicity was given recently in the press to the Gundaring and Kumerina finds, which are described below, Mr. G. E. Willard called upon me in regard to a meteorite which had fallen on Dalgaranga sheep station (27° 45′ S., 117° 5′ E.). He stated that when he was a manager of this station in 1923 he found a crater measuring 75 yards across at the top, 50 yards at the bottom, and 15 feet deep. The surface of the country was ‘hard conglomerate’ (laterite?—E. S. S.), and pieces of rock up to one cubic yard were pushed up out of the hole, as if there had been an explosion. The NW. side had been thrust upwards more than any other, indicating that the meteorite came from the SE. In and around the crater Willard found ‘a hatful’ of small ragged pieces of iron like the Henbury (Central Australia) fragments. These original specimens unfortunately had since been mislaid, but he was able to secure for me from the present manager of the station a 40-gram piece.

Work which has been in progress during the last few years on the low-grade regionally metamorphosed rocks of western Otago, New Zealand, has shown that members of the stilpnomelane group, hydrous iron- (or manganese-) rich silicates, are exceedingly widespread in rocks with the most varied mineral assemblages. In many cases the mineral in question is in sufficient quantity to rank as an essential constituent and may even be the most abundant one present. Hence in view of the importance of this mineral in the rocks of this region, it was considered that exact analytical data were necessary, and preliminary work in this connexion was carried out by Dr. F. J. Turner and the writer in 1934, but at that time, owing to the difficulties of separation, the pure minerals could not be obtained for analysis.

This amphibole is an important constituent of an albite-epidote-actinolite-chlorite-calcite-schist from the summit of Coronet Peak in the Wakatipu district, western Otago. The mineral is somewhat concentrated into folia and porphyroblastie crystals up to 5·0 mm. in length, and is markedly flattened parallel to the orthopinakoid so that sections cut parallel to the schistosity exhibit numerous porphyroblasts, deeply coloured, poorly birefringent, and showing rather poor cleavage lines (fig. 1 A and B; fig. 2 A). In slices cut across the foliation numerous elongated end-sections are to be seen with development of small orthopinakoids (fig. 2 B).

The refractive indices (±0·002) are α 1·635, β 1·650, γ 1·655; γ—α 0·020. The angle γ:c = 18° and 2V 60°±1° Pleochroism follows the scheme α pale yellow, β dirty bluish-green, γ deep bluish-green, with absorption γ > β > α.

The structures of the fibrous zeolites edingtonite, thomsonite, and natrolite (with scolecite and mesolite) were determined by X-ray methods some years ago, and it was suggested shortly afterwards by M. H. Hey and F. A. Bannister in a private communication to one of us (W.H.T.) that ‘ptilolite’, another zeolite of fibrous habit, might prove to have a similar structure. An X-ray rotation photograph about the needle axis indicated a unit-cell dimension along the needle axis of approximately 7·5 Å., quite different from the axis c 6·6 Å. characteristic of the fibrous zeolites previously examined, and no further examination of ‘ptilolite’ was made at that time. We have now determined the unit cell and space-group of this crystal, and further work is in progress with a view to the complete analysis of the structure. This paper presents an account of the experimental data which we have obtained.

In 1913 the late Mr. J. J. Beringer suggested that it would be of interest to determine the solubility of crushed felspar (a) in distilled water free of carbon dioxide, and (b) in distilled water saturated with carbon dioxide. For this purpose crushed felspar (orthoclase) was covered with water in a silica basin (i) in a desiccator containing potassium hydroxide solution, and (ii) in a desiccator connected with a carbondioxide Kipp's apparatus. These were allowed to stand for a fortnight and the alkalinity of the water Was then determined by N/100 hydrochloric acid. This experiment was continued until the end of July, 1914. A definite solubility was determined in each case and the solubility in the carbon dioxide water was only slightly more than in the water free from carbon dioxide. Unfortunately Mr. Beringer died early in 1915, and the records of his experiment could not be found.

Zinckenite was first described in 1826 by G. Rose, who determined it to be an orthorhombic mineral. The crystals were thought to be seldom single, but to occur in nearly hexagonal forms as a result of twinning in some fashion similar to that found in aragonite. The presence of longitudinal striations on the lateral faces was taken as further evidence that the crystals were twinned. The composition was given by H. Rose as PbSb2S4 or PbS.Sb2S3. The original specimens which were described came from the antimony mine of Woffsberg in the Harz.

In 1922 S. G. Gordon described a new lead sulfantimonite from Oruro, Bolivia, which he named keeleyite. This mineral he presumed to he orthorhombic, although no measurable crystals were found, and the formula was given as Pb2Sb6S11 or 2PbS.3Sb2S3.