Перед рентгенометрическим исследованием ставились следующие задачи: установить аморфную или кристаллическую природу образцов; выяснить, имеются ли существенные структурные изменения для различных образцов гуммитов, обособляемых по морфологическим признакам в разновидности; выявить, по возможности, причины структурных ’особенностей различных образцов; дать рентгенометрические эталоны для гуммитов, сравнив их с имеющимися в литературе результатами рентгенометрических исследований этих минералов; проследить характер изменений минералов при их термической обработке. Работа выполнялась в рентгенометрической лаборатории Федоровского института при Ленинградском горном институте в 1948 г.
Исследовалось 19 образцов ильменитов (табл. 1), из которых один образец 436а представлял собой кричтонит, т. е. ильменит, почти не содержащий магния, из дифференцированной трапповой интрузии на р. Аламжах, а остальные 18 образцов были отобраны с помощью элек тромагнита из протолочек кимберлита из алмазоносных трубок «Зарница» и «Мир» (Якутия). Из раздробленного ильменита отдельные фракции отбирались при различной силе тока в электромагните в интервале 0,4—1,2 а через каждые 0,1 а. Были подобраны две такие серии образцов по 9 фракций в каждой. Первая серия от И-1 до И-8 и И-19 представлена ильменитом из трубки «Мир», вторая — от И-9 до И-28 из трубки «Зарница». Для всех отобранных фракций был определен удельный вес.
Исследовалось несколько образцов шлиховой платины из дифференцированной интрузии габбро-диабаза, расположенной на территории Таймырского национального округа. Предварительно шлиховая платина была разделена на три фракции: электромагнитную (ЭМФ), магнитную (МФ) и сильномагнитную (СМФ).
В настоящее время ведется работа по составлению рентгенометрического определителя металлов и сплавов. Для каждого кристаллического вещества определяется характерная рентгенограмма. Изучение снимков рентгенограмм позволяет идентифицировать одинаковые вещества и различать неодинаковые. Самый процесс определения веществ заключается в получении и расчете рентгенограммы, а затем в сравнении полученных результатов с ранее снятыми эталонными рентгенограммами известных веществ. Совокупность эталонных рентгенограмм металлов и сплавов и составит рентгенометрический определитель металлов и сплавов.
Простые реберные формы тригональной и гексагональной сингоний. Для кристаллов тригональной и гексагональной сингоний нами выведено 90 простых реберных форм. В целях их классификации воспользуемся нумерацией и специальными символами, принятыми для тетрагональных форм.
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 in stealth from the Atlyansky placers. Since tin deposits in the central regions of the USSR have not yet been discovered, and geological equipment in the area of the Atlyan River is favorable for the formation of cassiterite deposits, it is necessary to deploy it.
Every year, the scope of application of X-rays to solve both theoretical and practical problems is expanding more and more. One of these problems is the use of X-rays for the purpose of identifying crystalline substances. The indispensability of the X-ray method of v-research has a particularly strong effect in geological and mineralogical in practice for a number of minerals of great industrial importance, such as iron, nickel, manganese, copper ores, clay and cement minerals, small fractions of rocks, ocher Mo-, Sb-, As-, W-minerals, etc. , due to the powderiness of the objects, all existing research methods (chemical, optical, mechanical and others) either cannot give positive results at all, or are used with great difficulty. In these cases, the only effective method is the X-ray method. Also, the only applicable X-ray method is when establishing. certain features or changes in the crystal structure of the substances being studied. When studying isomorphic groups of minerals, this method provides indispensable services in elucidating the characteristic features of isomorphic substitution and associated changes in the crystal structure. When studying a crystalline substance, the X-ray method should be used along with all existing research methods, because it makes it possible to establish perhaps the most important of all constants of a crystalline substance - the dimensions of the unit cell, and the arrangement of atoms or ions in the structure. The X-ray method of research is gaining increasing “authority” among chemists, mineralogists and mine workers. However, the widespread use of this method for identification circuits of crystalline substances is still greatly hampered by the lack of a more or less complete X-ray reference manual adapted for diagnostic purposes. The scattered works in the literature on individual minerals or groups of minerals, in which X-ray data were presented, did little to eliminate this shortcoming since, firstly, they were not adapted for identification purposes and, secondly, they affected a relatively small range of minerals. In later works of 1935-1936. some authors try to adapt x-ray data for identification purposes. However, in these works, the problem of creating an X-ray detector is solved only in a particular form - for certain groups of minerals studied by the authors.
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 the 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 Debyegrams of known minerals that could be assumed to be a given mineral. Similarly, when determining the mineral composition of a mixture, a Debyeogram is obtained from it and this latter is compared with the Debyegrams of those minerals whose presence was expected in the mixture. It follows that to apply this method it is necessary to have Debyegrams of known minerals as standards, with which the Debyegram of the analyzed substance is compared. In each individual area of application of the X-ray analysis method, a whole series of standard Debyegrams for a number of suspected substances must be prepared. At present, it is necessary to begin compiling an identification of substances based on their Debye patterns, similar to an identification of crystals based on goniometric data.
This work is one of the links in the chain to create an X-ray detector for minerals. The principles of constructing an X-ray detector, as well as the advantages of the X-ray method of powder in the diagnosis of minerals and in relation to deciphering the mineralogical composition of mixtures, are given in exhaustive detail by Prof. A.K. Boldyrev, V.I. Mikheev, G.A. Kovalev and V.N. Dubinina in the work “X-ray determinant of minerals” part I, so we will not touch on these issues here. We only note that at present the problem of creating an X-ray detector is so urgent that in a number of X-ray laboratories (Leningrad Mining Institute, Central Scientific Research Geological Prospecting Institute in Leningrad and the Institute of Applied Mineralogy in Moscow) the corresponding topic was put forward and work began directly on preparing material for the X-ray detector.
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 “Crystallographic Analysis” and to an even lesser extent in the version embodied in the “Identifier of Crystals” mentioned higher.
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 transmission 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 patterns. Complexes of characteristic lines for magnetite, diopside, augite and artificial enstatite were obtained.
