1941: Mineralogy

Conditions Abroad.

Research in mineralogy continued unabated in North and South America during 1941. On other continents, however, the effect of the second World War began to be felt. By the end of the year the inflow of mineralogical journals from German occupied Europe practically ceased.

On the other hand mineralogists elsewhere in Europe continued to carry on their research. The leading British journal in mineralogy continued to be issued promptly. The section devoted to annotated abstracts is slightly reduced, due no doubt to the lessened flow of publications from the continent. Late in 1940 a two-volume monograph on the minerals of the Swiss Alps was published in Switzerland. This represents a distinct contribution to the science, as the monograph covers in great detail some famous mineral deposits heretofore inadequately described. The Swedes were very active during 1941, publishing a series of papers on certain interesting mineral deposits in their country. The considerable lag in delivery of Russian publications prevents any statement as to their output, but the Russian mineralogists were still actively engaged in research in 1940.

Geological Society Semicentennial.

The present year was the semicentennial of the Geological Society of America, and this anniversary was marked by the publication of a volume on the progress made by the various geological sciences during the last half century. One chapter of the volume is devoted to Mineralogy, and another to Petrology. The author of the mineralogical chapter divides this science into its many branches, such as crystallography, optical mineralogy, chemical mineralogy, descriptive mineralogy and gem stones, tracing the development of each. He calls attention to the fact that many of the conclusions of the mineralogists of fifty years ago, based upon studies of the surfaces of crystals, but dealing with the internal structure of minerals, have been verified by recent researches conducted with the aid of X-rays. The petrology chapter, after discussing progress in petrography, a branch of petrology, and then describing the great strides made in recent years in utilizing physical chemical studies in the problem of the origin of rocks, considers the advances made in studying each of the three major rock groups, igneous, sedimentary, and metamorphic.. (See also GEOLOGY.)

Industrial Mineralogy.

Industrial mineralogy made great strides during 1941. No longer is spark plug porcelain made from the sillimanite minerals and andalusite, a process which led to an extensive search for these minerals two decades ago. Spark plugs are now made from alumina (aluminum oxide). The source mineral is bauxite, which has recently received much prominence as the sole ore of aluminum, a metal vital to the war industries. Toward the close of the year the press reported the development of a process to extract aluminum metal at a reasonable cost from clay, but this announcement has not yet been verified in the technical journals. It is a process, however, which the industrial scientists have been attempting to perfect for many years. Another recent development in the application of mineralogy to industry has been the use in abrasive wheels of diamonds, the hardest of all known substances. American-made synthetic sapphires and rubies are now being used as jewel bearings in electrical instruments. A German investigator reported in the Zentralblatt für Mineralogie early in 1941 on the hardness values of both natural minerals and synthetic minerals produced by electrochemical methods.

Scientific Investigations.

Purely scientific investigations have not been neglected. For example, mineralogists in collaboration with physicists and chemists have made extensive studies during the past year of the radioactivity of rocks, and the measurement of the age of these rocks by means of ratios obtained by chemical analyses.

Interest in meteorites continues unabated. Thirty-five papers on this fascinating subject were reviewed in a British abstract journal during the year. The presidential address of the retiring president of the Mineralogical Society of America, published early in 1941, was on the subject of problems in the study of meteorites. Fourteen essential minerals have been found in these 'celestial wanderers.' The former Keeper of Minerals in the British Museum published an account during the year of meteoric irons which have been discovered during the last century in a limited area in Great Namaqualand, Southwest Africa. About 30 of these meteorites, weighing more than 10 tons, were piled up in the Public Garden at Windhoek at the time of his visit. Many others had been removed from the country previously and sold to museums throughout the world. Furthermore, by no means all of these meteorites have been collected from the semi-arid area in which they fell. The writer of the article believes that a swarm of meteorites fell in this country in prehistoric time.

A drill hole near the center of a meteor crater in Ecton County, Texas, encountered the principal meteorite mass at a depth of 164 feet. The impact of this iron meteorite caused an outward tilting of the limestone bedrock.

Publications and Reports.

Interest continued through 1941 on the determination of internal crystal structures by means of X-rays. About 50 papers on this subject were reviewed in a British abstract journal. The same publication contained titles of 30 papers and one monograph on gems and precious stones. The monograph was 'The Story of de Beers,' a well-illustrated narrative of the discovery and mining of diamonds in South Africa. Among the papers were several on diamonds, including both the gem and industrial types, and on rubies, sapphires, emeralds, zircons, jade, opal, amethyst, agates, and turquoise. Six of these papers were concerned with North American localities. This is unusual, for our continent has relatively few precious stones.

A mineralogist and a chemist collaborated on a study of the types and causes of coloring in minerals which is a subject that has interested mineralogists ever since the beginning of the science. These investigators point out that it is possible to make a fundamental distinction between coloring due to absorption or reflection, which is dependent upon the chemical composition of the substance, and coloring which is caused by structural characteristics of the mineral.

Appearing in print in December 1940, too late for inclusion in last year's review, was an account of the discovery of natural sodium bicarbonate in large quantities at Searles Lake, Calif. A core drill exploring for marketable salts penetrated several rich beds of pure sodium bicarbonate at depths between 122 and 289 feet. An abundance of good crystals of this mineral were found in the core.

The origin of the rich nitrate deposits of Chile has long been a puzzle to the mineralogist. The most acceptable theories of the origin of these highly soluble salts have included concentration near the surface by ground waters. At the meeting of the Geological Society of America in the closing days of 1940 a geologist reported that examination of airplane photographs of this district shows that many of the deposits occur beneath surfaces which lie above the salt flats. This makes the ground water theory more difficult of application. Two other papers were presented at this meeting of special interest to mineralogists. One describes a possible new tool for the identification of polished specimens of opaque minerals under the microscope by measuring the 'reflectance,' or reflection of different wave lengths of light by means of suitable apparatus. The other paper describes the use of heavy minerals found in sedimentary rocks of the Atlantic Coastal Plain to determine the source of these sediments and thereby the geography of the past.

New Minerals.

Only 9 new minerals were listed in the American Mineralogist, the journal of the Mineralogical Society of America, during 1941. This sharp drop from the 27 listed the year before is without doubt due primarily to the absence of a number of foreign journals usually received during the year, in which many new minerals are described. Surprisingly enough the number of mineral names discredited during the year was also 9. These are minerals originally described as new, but later found by more detailed investigation to be identical with, or mere varieties of, older minerals.

Awards and Memorials.

The third Roebling medal of the Mineralogical Society of America, an outstanding award to mineralogists, was presented at the annual meeting of the Society to L. J. Spencer, retired Keeper of the Minerals at the British Museum but still an active mineralogist. Dr. Spencer has served as President of the Mineralogical Society of London, and is still editor of Mineralogical Magazine and Mineralogical Abstracts.

Several mineralogists died during 1940 and their memorials were published in 1941. Among those was W. C. Brogger, Professor Emeritus of the University of Oslo in Norway, who died at the age of 89. With his passing mineralogy lost not only its dean, but also one of its ablest investigators. The others listed were Lazard Cohn, American collector and crystallographer, Philip Krieger, economic geologist at Columbia University, and John E. Wolff, Professor Emeritus of petrography at Harvard University.