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Occasional Publication of the Bay Area Minerologists, No. 4 |
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A CHEMICAL-STRUCTURAL CLASSIFICATION OF MINERALS By Gail E. Dunning
INTRODUCTION
During the 1960's a project was begun to establish a numbering system for minerals in order to facilitate locating minerals in my personal collection. At that time Dana's System of Mineralogy was being used as the principal organizational medium. There was at that time, however, no systematic Dana classification of the silicate minerals existed. Using the System of Mineralogy of Dana as a beginning, six classes were established at the end of the System for the silicate minerals using an extension of the numbering system used for the non-silicate minerals. As the science of mineralogy evolved in the following years, a large number of mineral structures were solved. It soon became apparent that the general classification scheme used above was becoming outdated.
In the spring of 1995, with the acquisition of a Personal Computer, an effort was begun to formulate a new classification of the known minerals using a system that could be used with the computer, thus allowing sorting of minerals with their corresponding structural descriptions. This has been completed using both Microsoft Word and Excel programs and is presented here.
As the classification effort was begun, it became apparent that a single method of structural classification could not be applied uniformly to every chemical class. Therefore, each chemical class was treated individually. For example, the method of classifying the sulfosalts could not be used to classify the borates or any other oxygenated chemical class. Likewise, the silicates, which are based on the tetrahedral linkage of silicon and oxygen, offered a special application of structural classification based on linkage of silicon tetrahedron. With these restrictions in mind, a chemical-structural classification of minerals based on a computer-friendly designation system was begun.
This effort was aided by the published works of several authors who had established workable classification schemes for specific chemical groups, namely (1) The Silicates [Leibau (1985); Strunz (1986); Zoltai (1960); Belov (1965)], (2) The Borates [Christ and Clark (1977); Christ (1960); Burns et al. (1995)], (3) The Sulfides [Zoltai (1972)]; (4) The Sulfates [Sabelli and Trosti-Ferroni (1985)], (5) The Phosphates [Moore (1965)]. Each chemical class was given a unique letter designation beginning with the Elements (A) and ending with the Tectosilicates (Y). Within each chemical class, groups, types, and series were assigned in the same manor. This allows a maximum of 26 classes, groups, types, and series. Where there appeared more than 26 minerals per series, such as the amphiboles and other lengthy series of minerals, the extra minerals were designated to an overflow series. Since many minerals show isostructural properties between different chemical classes, those minerals are listed under each class where they are found to be isostructural but retain their unique letter designation based on their chemical class. Thus, silicate minerals that are isostructural with phosphate minerals are listed under both chemical groups. This allows the user an opportunity to examine the entire structural mineral series irrespective of chemical composition. When known, a short description of the mineral structure is given, allowing a glance at the atomic arrangement and the fundamental framework of each mineral or series of minerals.
The basic chemical-structural classification is recorded in Word and is arranged by ascending chemical complexity as was initially established by Dana's System of Mineralogy, except that some of the original classes have been combine to better see the relations of minerals. The silicate classes, originally six in number, has been reduced to five by combining the ortho-and sorosilicates into the more acceptable oligosilicate class. For ease of use, the Word version of the system has been converted into an Excel spread sheet format so that sorting can be used to view the total mineral population either as an alphabetic list, class list, or class letter list. The Form command allows the total data base to be examined on an individual basis.
Although this classification is far from representing an absolute structural organization of minerals, it is a logical beginning approach to a complex problem. In its present form, additions, modifications, and deletions are easily made and a total count of minerals is easily acquired. This system also allows a personal mineral collection to be computer-based using the five-letter mineral designation.
REFERENCES
Belov, N. V. (1965) Crystal chemistry of large-cation silicates. Consultants Bureau, New York.
Burns, P. C., Grice, J. D., and Hawthorne, F. C. (1995) Borate Minerals. I. Polyhedral clusters and fundamental building blocks. Canadian Mineralogist, 33, 1131-1151.
Christ, C. L. (1960) Crystal chemistry and systematic classification of hydrated borate minerals. American Mineralogist, 45, 334-340.
Christ, C. L. and Clark, J. R. (1977) A crystal-chemical classification of borate structures with emphasis on hydrated borates. Physics and Chemistry of Minerals, 2, 59-87.
Hawthorne, F. C. (1984) The crystal structure of stenonite and the classification of the aluminofluoride minerals. Canadian Mineralogist, 22, 245-251.
Hawthorne, F. C. (1985) Towards a structural classification of minerals: the VIMIVT2Ø n minerals. American Mineralogist, 70, 455-473.
Liebau, F. (1985) Structural chemistry of silicates. Springer-Verlag, New York.
Lime-de-Faria, J. (1994) Structural Mineralogy, An Introduction. Kluwer Academic Publishers, Dordrecht, The Netherlands, 344pp.
Moore, P. B. (1965) A structural classification of Fe-Mn orthophosphate hydrates. American Mineralogist, 50, 2052-2062.
Povarennykh, A. S. (1972) Crystal chemical classification of minerals. Plenum Press, New York, Vol. 1 & II.
Sabelli, C. and Trosti-Ferroni, R. (1985) A structural classification of sulfate minerals. Periodico di Mineralogie, 54, 1-46.
Strunz, H. (1986) Classification of the neso-and sorosilicates. Technical University, Berlin, Germany.
Zoltai, T. (1960) Classification of silicates and other minerals with tetrahedral structures. American Mineralogist, 45, 960-973.
Zoltai, T. (1974) Systematics of simple sulfide structures. University of Minnesota, Minneapolis.
The following outline illustrates the organization of the known mineral classes. Also included is the full classification of the Vanoxides as an illustration of the need to classify minerals structurally within a chemical class.
The complete mineral classification is available from the author as a Word document and as an Excel spreadsheet on a CD. Updates are done on a bimonthly schedule as new minerals or structures appear in the literature. It is anticipated that the update data may be presented on the Bay Area Mineralogists web site as a service to the members.
Contact via e-mail to the author may be made at «hyperlink "mailto:gedunning@juno.com" ».
CLASS CHEMICAL CLASS
A ELEMENTS (ALLOYS, CARBIDES, NITRIDES, PHOSPHIDES, SILICIDES)
B SULFIDES (SELENIDES, TELLURIDES, ARSENIDES, ETC.)
C SULFOSALTS
D OXIDES
E HYDROXIDES AND OXIDES CONTAINING HYDROXYL
F VANOXIDES
G HALIDES
H ALUMINO FLUORIDES
I HETEROPOLY ACID SALTS
J CARBONATES
K BORATES
L SULFATES
M PHOSPHATES, ARSENATES, VANADATES
N NITRATES
O IODATES
P SELENATES, TELLURATES, SELENITES, TELLURITES
Q CHROMATES
R ARSENITES
S MOLYBDATES, TUNGSTATES
T ORGANIC COMPOUNDS
U OLIGOSILICATES
V CYCLOSILICATES
W POLYSILICATES
X PHYLLOSILICATES
Y TECTOSILICATES
VANOXIDES
CLASS F VANOXIDES GROUP A LAYERED STRUCTURES
TYPE A -Li3V6O16 STRUCTURE TYPE SERIES A HEWETTITE Structure, mon/P21/m. FAAAA HEWETTITE CaV6O16.9H2 O FAAAB METAHEWETTITE CaV6O16.3H2 O FAAAC BARNESITE (Na,Ca)V6O16.3H 2O FAAAD HENDERSONITE Ca1.3 V6O16.6H2 O FAAAE GRANTSITE Ca1.3 V6O16.4H2 O
TYPE B -AgxV2O5 STRUCTURE TYPE SERIES A STRACZEKITE SERIES, mon/C2/m, Cc, C2/c FABAA STRACZEKITE (Ca,K,Ba)(V8O20).3H 2O FABAB CORVUSITE (Ca,Fe) V8O20. 8H2O FABAC FERNANDINITE Ca0.6 V8O20.10H2 0 FABAD BARIANDITE Al0.6 V8O20.18H2 0 FABAE BOKITE (Al,Fe)1.4(V,Fe)8O20 . 7.4H20
TYPE C NaxV2O5 STRUCTURE TYPE SERIES A SHCHERBINAITE SERIES, orth/Pmmn FACAA SHCHERBINAITE V2O5
TYPE D NaxV6O15 STRUCTURE TYPE SERIES A BANNERMANITE SERIES, mon/C2/m FADAA BANNERMANITE Na0.7V6O15
TYPE E V2O4 LAYER TYPE SERIES A SCHUBNELITE SERIES, tric/P1, mon FAEAA SCHUBNELITE Fe2-xV2O4(OH) 4 FAEAB FERVANITE Fe4V4O12. 5H2O
TYPE F V15O39 LAYER TYPE SERIES A KAZAKHSTANITE SERIES, mon/C2/c or Cc FAFAA KAZAKHSTANITE Fe5V34+V12 5+(OH)9.9H2O
SERIES B SATPAEVITE SERIES, FAFBA SATPAEVITE Al12V24+V6 5+O37.30H2O
TYPE G V10O24 LAYER TYPE SERIES A NAVAJOITE SERIES, mon/ FAGAA NAVAJOITE Ca0.05(V,Fe)10O24 .12H2O
TYPE H V4O10 (VO4 + V2O8) LAYER TYPE SERIES A MELANOVANADITE Structure, tric/P1. The structure contains a subcell with a layered structure in which the vanadate sheet consists of corner-shared tetrahedral VO4 and double square-pyramidal V2O8 groups, similar to that previously found in synthetic CaV2O5. The vanadate layers are separated by Ca ions and water molecules in a highly ordered arrangement. FAHAA MELANOVANADITE CaV4O10.10H2 O
TYPE I URANYL DIVANADITE LAYER COMPLEXES (V2O8) SERIES A CARNOTITE Structure, mon/P21/a. The structure is based on uranyl divanadite sheets laying parallel to (001), with K atoms and water molecules located in between these sheets. FAIAA CARNOTITE K2(UO2)2(V2 O8).3H2O FAIAB TYUYAMUNITE Ca(UO2)2(V2O8 ).9H2O FAIAC METATYUYAMUNITE Ca(UO2)2(V2O8 ).3H2O FAIAD STRELKINITE Na2(UO2)2(V2 O8).6H2O FAIAE MARGARITASITE (Cs,K,H3O)2(UO2) 2(V2O8).H 2O FAIAF FAIAG SENGIERITE Cu(UO2)2(V2O8 ).6H2O FAIAH CURIENITE Pb(UO2)2(V2O8 ).5H2O FAIAI FRANCEVILLITE (Ba,Pb)(UO2)2(V2O 8).5H2O FAIAJ VANURALITE Al(OH)(UO2)2(V2O 8).11H2O FAIAK METAVANURALITE Al(OH)(UO2)2(V2O 8).8H2O FAIAL VANURANYLITE (H,Ba,Ca,K)1.6(UO2)2 (V2O8).5H2 O
SERIES B RAUVITE SERIES FAIBA RAUVITE Ca(UO2)2V10O28 .16H2O
TYPE J V6O13 TYPE SERIES A VANOXITE SERIES FAJAA VANOXITE V6O13.8H2 O
GROUP B VANADATE CHAINS TYPE A ISOLATED VO3 TYPE CHAINS SERIES A ROSSITE Structure. Structure consists of metavanadate [VO3]n chains whose elements are square pyramids linked in a zig-zag manner by sharing edges (Munirite). The structure of rossite consists of oxygen atoms which are coordinated with V in the form of distorted rigonal bipyramids, and oxygen atoms and water molecules are coordinated with Ca in the form of distorted square antiprisms. Both in rossite and metarossite the trigonal bipyramids share edges to form double chains. These chains in rossite, however, are pairs joined by a shared edge.
FBAAA ROSSITE Ca[VO3]2.4H2 O tric/P1 FBAAB METAROSSITE Ca[VO3]2.2H2 O tric/P1 FBAAC DELRIOITE CaSr[VO3]2(OH)2 .2H2O mon/Ia, I2/a FBAAD METADELRIOITE CaSr[VO3]2(OH)2 .1H2O tric/P1 FBAAE MUNIRITE Na[VO3].2H2O orth/P21/a FBAAF METAMUNIRITE Na[VO3 ] orth/ FBAAG ALVANITE (Zn,Ni)Al4[VO3]2(OH) 12.2H2O mon/P21/n (unbranched zweier-single chain) FBAAH DICKTHOMSSENITE Mg(V+52O6). 7H2O mon/C2/c FBAAI RONNEBURGITE K2MnV4O12 mon/P21/n (unbranched vierer- Single chains
TYPE B OCTAHEDRAL CHAIN TYPE (Cu5V2O10) SERIES A STOIBERITE SERIES, mon/P21/n FBBAA STOIBERITE Cu5V2O10
SERIES B AVERIEVITE SERIES, trig FBBBA AVERIEVITE Cu5(VO4)2O2 . CuCl2
GROUP C ISO- AND HETEROPOLY MOLECULAR COMPLEXES TYPE A V10O28 TYPE SERIES A PASCOITE Series. The structure of sherwoodite consists of 8 molecules in the unit cell oined by Ca ions into chains along body diagonals, cross-linked to form an open framework of zeolitic character. The remaining Ca atoms and water molecules could not be resolved and are presumably in disordered array in the intermolecular channels. The V is partially reduced. The central figure of the structure is the 14vanadoaluminate group [AlV14O40]n-. The vanadium atoms are all in more or less distorted oxygen octahedra, and the 15 octahedra in the molecule are condensed into a dense structure in which the oxygen atoms are in a cubic-close-packed arrangement. The whole edifice may be considered a ragment of a NaCl type structure. FCAAA PASCOITE Ca3(V10O28). 17H2O mon/C2 FCAAB HUMMERITE K2Mg(V10O28). 16H2O tric/P1 FCAAC HUEMULITE Na4Mg(V10O28) .24H2O tric/P1 FCAAD SHERWOODITE Ca4.5(AlV14O40) .28H2O tetr/I41/amd
TYPE B V2O7 TYPE SERIES A PINTADOITE SERIES FCBAA PINTADOITE Ca2 [V2O7] FCBAB UVANITE U2V6O21. 15H2O FCBAC CHERVETITE Pb2V2O7 mon/P21/a
TYPE C V10O38 TYPE SERIES A VANALITE SERIES, mon/P2/m FCCAA VANALITE NaAl8V10O38. 30H2O Updated and printed 01/15/01 | ||