The following tasks were set before the X-ray radiometric study: to establish amorphous or crystalline nature of samples; to find out whether there are significant structural changes for different samples of gummites, isolated by morphological features into varieties; to identify, if possible, the reasons for the structural 'features of different samples; to give X-ray radiometric standards for gummites, comparing them with the results of X-ray radiometric studies of these minerals available in the literature; to trace the nature of changes in minerals at the and The work was carried out in the X-ray radiometric laboratory of the Fedorovsky Institute at the Leningrad Mining Institute in 1948.

Nineteen samples of ilmenite were studied (Table 1), of which one sample 436a was a krichtonite, i.e., ilmenite almost free of magnesium, from a differentiated trap intrusion on the Alamzhakh River, and the remaining 18 samples were collected with the help of an electromagnet from kimberlite flows from the Zarnitsa and Mir diamondiferous pipes (Yakutia). From crushed ilmenite, individual fractions were sampled at different current strengths in the electromagnet in the range 0.4-1.2 a every 0.1 a. Two such series of samples of 9 fractions each were selected. The first series from I-1 to I-8 and I-19 is represented by ilmenite from the “Mir” tube, the second - from I-9 to I-28 from the “Zarnitsa” tube. Specific gravity was determined for all selected fractions.

Several samples of schlich platinum from a differentiated gabbro-diabase intrusion located in the Taimyr National District were studied. The schlich platinum was preliminary divided into three fractions: electromagnetic (EMF), magnetic (MF) and strongly magnetic (SMF).

At present, work is underway to compile a radiometric identifier of metals and alloys. For each crystalline substance a characteristic X-ray diagram is determined. The study of X-ray images allows identifying the same substances and distinguishing between dissimilar ones. The very process of determining substances consists in obtaining and calculating X-ray images and then comparing the results with previously taken reference X-ray images of known substances. The totality of reference X-ray radiographs of metals and alloys and will constitute the X-ray determinant of metals and alloys.

Simple rib shapes of trigonal and hexagonal syngonies. For crystals of trigonal and hexagonal syngonies we have derived 90 simple rib shapes. In order to classify them, we will use the numbering and special symbols adopted for tetragonal forms.

Crystal identification tables showed that five crystals of the mining museum N 110/1-4 and 110/8, which were stored as rutile, do not differ from cassiterite crystals. It is also known that these cassiterite crystals were formed from the Atlyan placers of the Southern Urals. When examining the Eremeevskaya collection of the mining museum, cassiterite was also discovered on a shelf from the Atlyan placers. Since no tin deposit has yet been discovered in the central regions of the USSR and the geological conditions in the Atlyan River district are favorable for the formation of cassiterite deposits, detailed prospecting work must be undertaken in this district.

From year to year the sphere of application of X-Rays to the solution of both theoretical and practical problems becomes wider and wider. Thus the X-Rays are now applied for the purpose of identification of crystalline substances. The unequaled excellence of the X-Ray method is particularly manifest in geology and mineralogy. For a long series of minerals of vase industrial importance, as iron, nickel, manganese, and copper ores, clay and cement minerals, fine fractions of rocks, ochrous Mo-, Sb-, As-, W-minerals, etc. all other methods of investigation (chemical, optical, mechanical, etc.)' because of the pulverulent character of the objects, can give no positive results or meet with great difficulties in their application. In these cases the X-Ray method is the only efficacious method of investigation. It proves also to be the only method to apply in determining such and such peculiarities or changes in the crystalline structure of the substances under consideration. In the study of isomorphic groups of minerals this method renders unique services in clearing up the characteristic peculiarities of isomorphic replacement and changes in crystalline structures which are connected therewith. In every investigation of crystalline substances the X-Ray method must be applied side by side with all other methods of investigation, because it gives the possibility of ascertaining the most important, perhaps, of all the constants of a crystalline substance, namely the dimensions of the elementary cell and the scheme of the position, of atoms or ions in the structure. The X-Ray method of investigation acquires greater and greater authority with chemists, mineralogists and miners. Yet a wide application of this method for the purpose of identification of crystalline substances has been till now greatly hindered by the absence of more or less comprehensive X-Ray determinative tables adopted to the purpose of X-Ray mineralogical diagnostics. Disconnected works on separate minerals, or groups of them, scattered in literature though containing some X-Ray data, did but little to eliminate this defect, because, first, they were not adopted to the purpose of identification, and, secondly, they concerned a comparatively small number of minerals. In later works of 1935 and 1936 some authors try to adopt X-Ray data to the purpose of identification, but in these works the problem of producing any X-Ray determinative tables is solved only under a particular form, for a separate group of minerals studies by the authors. The present work constitutes the second issue of the X-ray determinator.

In the field of geological and mineralogical work, X-ray measurements can have a wide and varied application. In X-ray measurements, there are several methods for studying crystalline matter. The main methods are: the Laue method, the crystal rotation method, the Debye‑Scherrer‑Hall method (or powder method), and the Bragg method. To determine a given mineral, it is necessary to grind it into powder, obtain a Debyeogram from it and compare it with the Debyeograms of known minerals that could be presumed to be the given mineral. Similarly, when determining the mineral composition of a mixture, a Debyeogram is obtained from it and this latter is compared with the Debyeograms of those minerals whose presence was expected in the mixture. It follows that to apply this method it is necessary to have Debyeograms of known minerals as standards, with which the Debyeogram of the analyzed substance is compared. In each individual area of application of the X‑ray analysis method, a whole series of standard Debyeograms for a number of suspected substances must be prepared. At present, it is necessary to begin compiling a determinant of substances based on their Debyeograms, similar to a determinant of crystals based on goniometric data.

By means of the (Debay-Scherrer-Hull) powder method have been investigated fourteen minerals of the class of oxides. In the present paper are given exact values of the interplanar distances and relative intensities of lines, for the following minerals: thorite, cassiterite, polyanite, ilmenorutile, wood-tin, pyrolysite, thorianite, uraninite, nasturan, senarmonitite, arsenolite, claudetite and Sb-ocher. The tables given in this paper may be considered as material for "Röntgenometrical Determinative Tables of Minerals". Besides, there are also given models of tables and methodology of preparation of powder diagrams which will be useful in the future work as example on the composition of "Röntgenometrical Determinative Tables of Minerals".

At the beginning of this century, E. S. Fedorov created a method for determining a substance by the shape of its crystals, which he called “Crystal-chemical analysis” (29). This method, based on measuring the angles between the outer faces of crystals, was an important fundamental and practical achievement of crystallography. Over the next few years, this method, which in its essence is best called goniometric diagnosis, was significantly simplified by Fedorov’s school. Currently, the Fedorov Institute and the Central Geological Prospecting Institute (TsNIGRI) are compiling a “Crystal Determinant” (2), which will enable goniometric diagnosis in its new version to enter, along with optical diagnosis, into the daily practice of a crystallographer, chemist, and mineralogist. The main advantages of goniometric diagnosis are the complete absence of substance consumption, comparative speed of determination and the same degree of simplicity of diagnosis both in the case of simple and in the case of extremely complex substances. The main disadvantages of the goniometric method are the need to have the substance in the form of crystals and the variability of the external shape of crystals of the same substance. The second drawback may in some cases make it impossible to determine the substance by goniometric method. This drawback is especially noticeable in Barker’s version (16) of the goniometric diagnosis (20, 328, 329), to a somewhat lesser extent in Fedorov’s “Crystallochemical Analysis” and to an even lesser extent in the version embodied in the “Identifier of Crystals” mentioned above.

This note is a report of preliminary results of X-ray examination of stone casting samples. The issue of X-ray examination of stone castings is not covered in the literature, and therefore our work represents the first attempt to use X-rays in this area. Meanwhile, with the help of X-rays, a number of problems could be solved here, such as: determination of minerals in stone casting products in the fine-crystalline phase, determination of the degree of crystallization, determination of the dispersion value of particles of the crystalline phase, etc., not to mention the radiography of castings. Our work was intended to mainly determine the minerals that arise during the crystallization of diabase smelting products at different temperatures and annealing conditions. Complexes of characteristic lines for magnetite, diopside, augite and artificial enstatite were obtained.