Augelite was originally described from Sweden by Blomstrand (1868) who obtained the composition 2Al2O3.P2O5.3H2O from a massive mineral with cleavage in three directions. No further description of this inadequately defined mineral appeared until Prior and Spencer (1895) gave their complete and exact characterization of well-crystallized material from Machacamarca, department Potosi, Bolivia, supplemented by observations by Spencer (1898, 1907) on further finds at Tatasi, department Potosi, and at Oruro, Bolivia.

Lemmon (1935) first recognized augelite as cleavage masses in the commercial deposit of andalusite at White Mountain, Mono County, California, and gave determinative observations which established the identity of the mineral. In this locality Kerr (1932) had noted corundum, diaspore, pyrophyllite, alunite, lazulite, and rutile, associated with the andalusite. In addition to these minerals Professor Joseph Murdoch of the University of California at Los Angeles, has found small, white, tabular crystals of apatite in a specimen carrying augelite. Crystals of augelite from this deposit, with a number of new forms, were mentioned by Pough (1936) in an inconspicuous notice which we did not see until our work was nearly done.

The determination of ferrous iron in minerals, such as staurolite and kornerupine, which cannot be effectively dissolved by dilute sulphuric and hydrofluoric acids has been made possible on the macro-scale by the work of H. P. Rowledge; the mineral is fused with sodium fluoride and boric oxide at 900°C. in a sealed pyrex glass tube, the fusion cake dissolved in hot dilute sulphuric acid in a current of carbondioxide, and the solution titrated with potassium permanganate. We have met with no difficulty in applying the method on the macro-scale, but when only small amounts of a mineral are available several difficulties arise, and modifications become necessary.

The air present in the sealed tube of a Rowledge fusion, using the quantities and dimensions he specifies, is already sufficient to oxidize about 3 to 5 mg. of ferrous oxide. But when the weight of the sample is reduced to 10 mg., it is not possible to reduce the dead-space in the tube in proportion ; it can hardly be reduced below about ¼c .c. which is sufficient to oxidize 0·3 mg. or 3% FeO and is likely to be more effective in this direction than on the larger scale, since the surface of the fusion is proportionally greater.

Some years ago, when working through large parcels of mixed faceted gem-stones in a search for blue spinels of high refractive index, several unusual specimens were encountered, two of which were later identified as kornerupine by Dr. G. F. Claringbull, using X-ray methods. The other stones in these parcels were all quite typical products of the Ceylon gem gravels, consisting mainly of zircons, garnets, and spinels. Since kornerupine is so rare a mineral, and had not previously been reported from Ceylon, it was considered worth while to attempt to place the new occurrence beyond doubt by searching through rough gem gravel imported direct from Ceylon. This was made possible by the kindness of Mr. Hans Van Starrex, who sent a consignment weighing several pounds from the Matale district (Anderson and Payne, 1940).

During the X-ray study of a new phosphate mineral, not yet published, the usual comparison was made with cell-side measuremerits of related minerals. One of these is ‘eggonite’, a rare hydrous aluminium phosphate said to occur on silver ores at Felsőbánya, Hungary. Rotation photographs of ‘eggonite’ are different from those of the new mineral, but yielded dimensions close to those of sterrettite, a new mineral from Fairfield, Utah, described last year by Larsen and Montgomery. These authors generously presented a specimen of sterrettite to the British Museum, and rotation photographs taken in the Mineral Department not only give cell-dimensions close to those published but also identical with those of ‘eggonite’. A brief account of this identification is now given not only to justify abandoning the mineral name ‘eggonite’, but also to place on record a European occurrence of a rare mineral so far described from only one American locality.

The present communication deals with a calc-silicate hornfels of uncommon mineralogical and chemical composition. It may be tentatively referred to the deep-seated metamorphism of a marl, and on account of the shortage of analytical data pertaining to metamorphosed sediments of the calcareo-argillaceous type, a detailed investigation of a variety of this group seems justified.

Intercalated bands of anorthite-epidote-garnet-hornfels bordered bilaterally by pyroxene-bearing gneisses occur on the farms Zandfontein, Pella, and Klein Pella in the north-eastern part of the division of Namaqualand, South Africa (cf. geological map), On Klein Pella small exposures also extend intermittingly for approximately 1·5 miles due WNW.-ESE. of the amphibolite koppie situated on the northern boundary of the farm area. The bands exhibit a gentle pinch and swell structure with maximum widths of 15 to 41 inches, and the contact with the host rock is commonly marked by an epidotic fringe ¾ inch in thickness. In some cases the anorthite-epidote-garnet-rock is penetrated by parallel lenticles of pure quartz which may attain maximum breadths of 0·8 inch.