Organization :
In this publication measurements of interfacial angles of crystals are used to classify and identify chemical substances .
T. V. Barker , who developed the classification-angle system , was about to begin the systematic compilation of the index when he died in 1931 .
The compilation work was undertaken by a number of interested crystallographers in the Department of Mineralogy of the University Museum at Oxford .
Since 1948 the working headquarters has been the Department of Geology and Mineralogy .
Numerous cooperating individuals in Great Britain , Holland , the United States , and Belgium have contributed editorially or by making calculations .
Great interest and practical help have been given by the Barker Index Committee .
Financial and material help have come from academic , governmental , and industrial organizations in England and Holland .
Editors for Volumes 1 , and 2 , were M. W. Porter and the late R. C. Spiller , both of Oxford University .
A third volume remains to be published .
Substances :
Volume 1 , deals with 2991 compounds belonging to the tetragonal , hexagonal and trigonal , and orthorhombic systems ; ;
and Volume 2 , , with about 3500 monoclinic substances .
Volume 3 , , in preparation , will treat the anorthic compounds described in Groth's Chemische Krystallographie .
Properties :
The Barker system is based on the use of the smallest number of interfacial angles necessary for indexing purposes .
Other morphological , physical , and optical property values are also given .
Sources of data :
The index is essentially a new treatment of previously compiled morphological data .
Most of the data used are from Groth's Chemische Krystallographie .
Criticality :
Every calculation has been made independently by two workers and checked by one of the editors .
Use of nomenclature , symbols , units , physical constants :
Accepted crystallographic symbolism has been used ; ;
other symbols related to the index necessarily have been introduced .
Currency :
This publication covers the old literature ( Groth ) ; ;
there is no mechanism for keeping the volumes up to date .
Format :
The publication form is that of clothbound books .
The data are presented in lists and tables .
Part 1 in both volumes is labeled `` Introduction And Tables '' .
The tables include those for the classification angles , refractive indices , and melting points of the various types of crystals .
Part 2 of Volume 1 , and Parts 2 and 3 of Volume 2 , contain the crystal descriptions .
These are grouped into sections according to the crystal system , and within each section compounds are arranged in the same order as in Groth's Chemische Krystallographie .
An alphabetical list of chemical and mineralogical names with reference numbers enables one to find a particular crystal description .
References to the data sources are given in the crystal descriptions .
Publication and distribution :
The Barker index is published for the Barker Index Committee by W. Heffer & Sons , Ltd. , 4 Petty Cury , Cambridge , England .
Volume 1 , containing Parts 1 and 2 was published in 1951 ; ;
Volume 2 , , in three parts , in 1956 .
The two volumes are available from the publisher for $16.80 and $28.00 , respectively .



2-2 .
Crystal data
organization :
The present edition of crystal data was written by J.D.H. Donnay , the Johns Hopkins University , Baltimore , Md. ( Part 2 ) ) and Werner Nowacki , University of Berne , Switzerland ( Part 1 ) ) with the collaboration of Gabrielle Donnay , U. S. Geological Survey , Washington , D. C. .
Many collaborators in the United States and Switzerland helped in collecting and assembling data , in making calculations , and in editing .
Support came from academic and industrial groups in these two countries .
The Geological Society of America gave a grant-in-aid to complete the work and bore the expenses of publication .
Preparation of a second edition is in progress under the sponsorship of the Crystal Data Committee of the American Crystallographic Association .
Coeditors are J.D.H. Donnay , G. E. Cox of Leeds University , and Olga Kennard of the National Council for Medical Research , London .
Financial grants have been received from the National Science Foundation and the ( British ) Institute of Physics for the compilation work and the publication costs .
The continuity of the project is suggested by plans for an eventual third edition .
Substances :
Elements , alloys , inorganic and organic compounds .
( Metal data will not be included in the second edition , since these have been collected independently by W. B. Pearson , National Research Council , Ottawa , and published as A handbook of lattice spacings and structures of metals and alloys by Pergamon Press .
) properties :
Crystallographic data resulting mainly from X-ray and electron diffraction measurements are presented .
Cell dimensions , number of formula units per cell , space group , and specific gravity are given for all substances .
For some substances , auxiliary properties such as the melting point are given .
Sources of data :
Part 1 , of the present edition covers the literature to mid-1948 ; ;
Part 2 , , up to the end of 1951 .
Much of the material comes directly from secondary sources such as Strukturbericht .
Criticality :
The vast number of compounds to be covered , the limited resources to do the job , and the immediate need for this type of compilation precluded a thorough evaluation of all available data in the present edition .
Future editions may be more critical .
Use of nomenclature , symbols , units , physical constants :
Since Parts 1 , and 2 , were prepared independently , the abbreviation schemes and the chemical symbols used differ in the two parts .
The second edition should have greater uniformity .
Currency :
A second edition is in preparation , and there are long range plans for a third .
Format :
Data in the present edition are presented in tables and lists .
Part 1 , deals with the classification of crystalline substances by space groups and is not a numerical data compilation .
The compounds are divided according to composition into seven categories .
Part 2 , contains determinative tables for the identification of crystalline substances .
These are arranged according to crystal system .
There are formula and name indexes covering both parts .
References for Part 1 , are given at the end and for Part 2 , in the tables .
Publication and distribution :
The present edition of crystal data ( Af ) , published in 1954 as Memoir 60 of the Geological Society of America , is now out of print .
The manuscript of the second edition will probably be ready by the end of 1960 .



2-3 .
Crystal Structures
organization :
The author of Crystal Structures is Ralph W.G. Wyckoff , University of Arizona , Tucson , Arizona .
The first section of this publication appeared in 1948 and the last supplement in 1960 .
Though now complete , the publication is included in this directory because of its importance and because of the long-term nature of its preparation .
Substances :
Elements , inorganic and organic compounds ( no alloys ) .
Properties :
The data presented are derived almost entirely from X-ray diffraction measurements and include atomic coordinates , cell dimensions , and atomic and ionic radii .
Sources of data :
Published literature .
Criticality :
The aim was to state the results of all available determinations of atomic positions in crystals .
Presumably the tabulated data are best available values .
The critical comments in the textual sections of this publication are invaluable .
Use of nomenclature , symbols , units , physical constants :
The terminology used conforms to that of Internationale Tabellen Zur Bestimmung Von Kristallstrukturen .
Currency :
During the years of publication , supplement and replacement sheets were issued periodically .
Coverage of the literature extends through 1954 and includes some 1955 references .
It is to be hoped that some way will be found to keep this important work current .
Format :
The publication form is that of loose-leaf sheets ( Af ) contained in binders .
The book is divided into chapters and in each chapter the material is grouped into Text , Tables , Illustrations , and Bibliography .
Each group is paginated separately ; ;
numbers sometimes followed by letters are used so that insertions can be made .
Inorganic structures are found in Chapters 2 - 12 , organic structures in Chapters 13 - 15 .
Within each chapter an effort has been made to group together those crystals with similar structures .
There are three indexes , i.e. , an inorganic formula index , a mineralogical name index , and a name index to organic compounds .
Publication and distribution :
Publisher of Crystal Structures is Interscience Publishers , 250 Fifth Avenue , New York 1 , N. Y. .
The work consists of four sections and 5 supplements .
Price of the complete work including all necessary binders is $148.50 .



2-4 .
Dana's System Of Mineralogy
organization :
Six editions of James Dwight Dana's System appeared between 1837 and 1892 .
In 1915 Edward S. Dana , editor of the sixth edition , asked W. E. Ford of Yale University to prepare a seventh edition of his father's work .
A number of people became involved in the preparation but work was slow until 1937 .
In that year a grant was obtained from the Penrose Fund of the Geological Society of America to finance additional full-time workers .
Money was also advanced by the publishers , John Wiley & Sons , Inc. .
Volume 1 , was completed in 1941 and published in 1944 .
The editors of this volume and Volume 2 , were the late Charles Palache , Clifford Frondel , and the late Harry Berman , all of Harvard University .
Work on Volume 2 , was begun in 1941 , interrupted by the war in 1942 , and resumed in 1945 .
The volume was completed in 1950 and published in 1951 .
A supplementary grant from the Geological Society of America helped finance its publication .
Besides the editors there were many contributors in the United States and Great Britain to Volumes 1 , and 2 .
W. E. Ford , for example , continued to supply data on the occurrence of minerals until his death in 1939 .
Volume 3 , is nearing completion and there are plans to revise Volume 1 .
The project is currently supported by Harvard University .
Substances :
minerals .
Properties :
Crystallographic , physical , optical , and chemical properties .
The crystallographic data given include interaxial angles and unit cell dimensions ; ;
the physical property values include hardness , melting point , and specific gravity .
Sources of data :
Almost entirely original articles in journals ; ;
abstracts and other compilations on rare occasions when original papers are not available .
Criticality :
All information is carefully appraised and uncertain facts are designated by ( '?' .
) An authentic diffraction pattern is always obtained and optical properties are frequently checked .
Use of nomenclature , symbols , units , physical constants :
Recommendations of international authorities , such as the International Union of Crystallography , are followed .
There is a complete synonymy at the beginning of each species description .
Currency :
Currency in the usual sense cannot be maintained in an undertaking of this sort .
Format :
The data are presented in text and tables in bound volumes .
Volume 1 , of the seventh edition contains an introduction and data for eight classes of minerals ; ;
Volume 2 , contains data for forty-two classes .
References are given at the end of each mineral description and a general index is given at the end of each volume .
There will be a comprehensive index in Volume 3 , covering all three volumes .
Publication and distribution :
Volume 1 ( ( Af ) of the seventh edition of Dana's System Of Mineralogy was published in 1944 and Volume 2 ( ( Af ) in 1951 by John Wiley & Sons , Inc. , New York , N. Y. .
( The association of Wiley & Sons with the Dana Mineralogies dates back to 1844 when they published the second edition of the system .
) The two volumes are available from the publisher for $14.00 and $16.00 , respectively .



2-5 .
The Groth Institute
organization :
`` The Groth Institute '' , which was established in 1958 , is a group activity affiliated with the Physics Department of The Pennsylvania State University , University Park , Pa. .
Ray Pepinsky is the Director .
The Institute derives its name from Paul Von Groth's Chemische Krystallographie , a five-volume work which appeared between 1906 and 1919 .
The resident staff is large and consists of professional assistants , graduate students , abstractors , librarian , technical editor , machine operators , secretarial help , and others .
There are also corresponding members and outside advisory groups .
The Air Force Office of Scientific Research has provided financial assistance in the early stages of the Institute's program .
Substances :
All crystalline substances and other solid-state materials .
Properties :
The aim is to collect a very broad range of physical , chemical , morphological , and structural data for crystals on an encyclopedic scale and to seek all possible useful and revealing correlations of properties with internal structure .
Sources of data :
The first stage of operation has centered on the literature imaging of critical or summarizing tabulations such as the Barker Index .
Coverage of primary literature will follow .
Unpublished data will be available to the Groth institute from cooperating groups and individuals .
Criticality :
Critical evaluation of all data compiled is not a primary aim of this project .
However , the proposed correlation of the many interrelated properties of crystals will reveal discrepancies in the recorded data and suggest areas for reinvestigation .
In addition , the availability of computers will permit recalculation and refinement of much structural information .
Use of nomenclature , symbols , units , physical constants :
For punched-card or tape storage of information all literature values must be conformed to a common language .
In this way a degree of unification of nomenclature , symbols , and units will be realized .

