THE COMMISSION ON NEW MINERALS AND MINERAL NAMES( CNMMN )
OF THE INTERNATIONAL MINERALOGICAL ASSOCIATION( IMA )
CRITERIA FOR THE DEFINITION OF A NEW MINERAL
PROCEDURE FOR THE VALIDATION OF A NEW MINERAL
CHOICE OF NAME
CONTINUATION OF THE PROCEDURE
The creation of an international authority for the purpose of controlling new minerals and their names appeared to be essential in the eyes of numerous mineralogists, in order to avoid the presently existing confusion in this field. Until 1959, when the IMA was created, there were no strict rules regulating the definition of new mineral species. New names were created by researchers themselves, with all possible risks arising from erroneous or incomplete descriptions, or from using already existing names. M. Fleischer ( 1961 ) thus notes that out of 583 new minerals recorded between 1940 and 1959, 106 appeared to be identical to already existing minerals, 97 were mere varieties and 69 descriptions were incomplete. As a result, 46% of the species were of a dubious validity. Another good example of the confusion in the nomenclature is illustrated by cordierite: this mineral has received 23 different names belonging either to local varieties, or to species with only slight differences in the chemical composition or physical properties. Moreover, there existed no guarantees as to the conservation of the type material, which made all subsequent comparisons with new material hazardous.
The IMA was established in 1959 and its Commission on New Minerals and Mineral Names was entrusted with the control of the new species and their nomenclature. The first meeting took place in Copenhagen, in 1960 , where the functioning rules of the association had been defined. In 1962, during the meeting held at the Smithsonian Institution in Washington, the members of the Commission attending the meeting expressed their first vote: the new international system of approval of new minerals was thus inaugurated by roquesite.
The present functioning rules of the CNMMN are the result of successive conventions, continuously improved and adapted according to new analysis techniques. We may quote the successive works of Hey et al ( 1961 ), Fleischer ( 1970 ), Donnay and Fleischer ( 1970 ), Mandarino et al ( 1984 ), Nickel and Mandarino ( 1987 ), Dunn and Mandarino ( 1988 ) as well as the last adaptation by Nickel ( 1996 ).
The executive committee of the Commission consists of a chairman, a vice-chairman and a secretary, elected by the members of the Commission and entrusted with the following well-defined tasks:
- the chairman is responsible for all matters concerning new minerals and their nomenclature;
- the vice-chairman deals with proposals of disregard, redefinition and revalidation of minerals;
- the secretary functions as a link between the subcommissions with the task of reorganising mineral groups ( amphiboles, micas ) and is charged with administrative duties for the Commission.
Beside the officials, the Commission consists at present of 29 national delegates representing the following countries: the Republic of South Africa, Australia, Austria, Belgium, Brazil, Bulgaria, Canada, China, Croatia, the Czech Republic, Denmark, Finland, France, Germany, Hungary, Israel, Italy, Japan, the Netherlands, New Zealand, Norway, Poland, Romania, Russia, Spain, Sweden, Switzerland, United Kingdom and the United States.
CRITERIA FOR THE DEFINITION OF A NEW MINERAL
A mineral can be described as a solid, inorganic and crystallised substance having a well-defined chemical composition and physical properties. It is the result of a terrestrial or extra-terrestrial geological process, with no intervention of Man. Metallurgical slags and chimney deposits are therefore not considered as minerals.
A new mineral must necessarily have a chemical composition and crystallographic properties which are different from those of the already existing species. As stated by Nickel ( 1996 ) a very slight variation in the chemical composition may justify a new species, provided that a minor element stabilises the structure, or that its presence in a certain site causes structural modifications linked to its charge or to its different size. On the other hand, an element may partly substitute another, but this must not necessarily result in major structural modifications. In this case, the chemical varieties are designated by only one mineral name accompanied by a chemical adjective; for example: nickel-pyrite. The problem of minerals having the same chemical composition but crystallising in different systems is more delicate to solve. According to the case, either two different minerals will be distinguished [ ex.: pyrite ( cubic ) and marcasite ( orthorhombic ), diamond ( cubic ) and graphite ( hexagonal )], or only one single species, ex.: analcime, having cubic, tetragonal, monoclinic, etc., polymorphs, depending on minor variations in the ordering of the cathions Al and Si in the structure. Some polymorphs and the polytypes ( compounds characterised by a different periodicity in the stacking of layers ) are designated by an only name of species followed by a structural suffix, ex.: heterogenite-2H and heterogenite-3R, lepidolite-2M1 and lepidolite-3T.
PROCEDURE FOR THE VALIDATION OF A NEW MINERAL
A mineralogist who wishes to have a new mineral officially recognised, should submit a proposal to this effect to the chairman of the CNMMN. He should fill in a type form for this purpose, indicating the following indications:
- the proposed name for the new mineral ( this point will be discussed more in detail below );
- the precise geographic occurrence: country, province or state, locality, mine, or the geographic co-ordinates in case toponymic references are lacking. Additional data to be mentioned here are the geological context, paragenesis and associated minerals;
- the chemical composition accompanied by the formula, as well as by the method of analysis;
- crystallography: system, class, space group, unit-cell size, volume, number of formula units per unit cell ( Z ) and X-ray diffraction powder diagram;
- the crystal structure, when permitted by the morphology of the crystals;
- the macroscopic description and physical properties: morphology, crystal size, colour, lustre, fracture, cleavage, hardness, measured density, calculated density;
- optical properties. A different form is filled in, depending on whether the mineral is transparent or opaque:
Non-opaque mineral: isotropic or anisotropic, uniaxial or biaxial, optical sign, indices of refraction, 2V angle, dispersion, pleochroism, absorption, orientation with respect to crystallographic axes;
Opaque mineral: colour in reflected light, internal reflections, isotropic or anisotropic, bireflectance, indices of reflection measured under different wavelengths;
- other data: thermal behaviour ( thermogravimetric and differential analyses, infrared spectrum, fluorescence under UV light ), magnetism, radioactivity;
- conservation of type material: place of conservation ( necessarily a recognised national collection );
- relationship to other species;
- bibliographic references.
CHOICE OF NAME
The problem of the choice of a name for a new mineral deserves a more detailed discussion. In the first place, the name should be sufficiently different from the already existing minerals ( indeed, langbå nite and langbeinite may give rise to confusion, just like smithite and smythite ).
Homonyms will be distinguished by adding the first name to the surname of the chosen person: youngite and brianyoungite, melonite ( after the mine Melones in California ) and melonjosephite ( after Joseph Mélon ). Care should also be taken that a name deriving from a language such as Chinese or Russian is not too difficult to pronounce by someone of Latin or Anglo-Saxon origin ( ex.: przhevalskite or xiangjiangite ). In any case, a transliteration into the Latin alphabet should be provided. It is, however, also true that names such as vandendriesscheite or haapalaite must be equally arduous to Asiatic readers.
The name for a new mineral should, however, be imperatively chosen taking into account one of the following four criteria:
1. Dedication to a personality prominent in the field of mineralogy or a related science ( ex.: haüyne, mandarinoite ). The chosen personalityís permission must be obtained to this effect. It should be absolutely avoided to name a mineral after a personality from the political, artistic or sportís sphere, although this had happened in the past ( ex.: nyerereite, after the Tanzanian president Julius Nyerere ).
2. Allusion to the morphology or a physical property of the mineral. In such a case, Greek and/or Latin roots are most often juxtaposed ( ex.: astrocyanite-(Ce), designating blue-coloured rosettes).
3. Allusion to the chemical composition of the mineral, often by juxtaposing chemical symbols
( ex.: tantalite, umohoite, containing U, Mo, O and H ).
4. Name of the geographical locality of the occurrence: country, province, locality, mine, river
( ex.: tunisite, coloradoite, kipushite).
The etymology of certain names which may date back to the Antiquity does not correspond to the above-mentioned criteria [ ex.: galena ( Pliny, 77 A.D. ), cinnabar ( Theophrastus, 315 B.C. )]
An already existing name may also be modified by the addition of prefixes such as clino-, ortho-, para-, meta-, pseudo-, implying structural modifications, a dehydration or similarities with an already existing mineral ( ex.: clinochalcomenite, pseudomalachite ). A suffix may also distinguish two minerals belonging to the same group but having a different chemical composition. This is the case, namely, of Levinsonís symbols used for rare-earth minerals
[ ex.: florencite-(La) and florencite-(Ce)]
CONTINUATION OF THE PROCEDURE
The form containing as much information as possible about the new mineral is sent to the chairman of the Commission. At this stage, he is authorised to ask further information from the author. The chairman of the CNMMN then writes an abstract which he sends to different national delegates who should express a vote ( yes, no, abstention ), accompanied by possible comments, within a period of two months.
A proposed new mineral will be considered approved if two thirds of the expressed votes are in favour of the proposal and if at least half of the national delegates have voted. A proposed name is accepted if 50% of the votes expressed by at least half of the delegates are in favour of it. An abstention is regarded as a negative vote.
The chairman of the Commission then sends the results of the voting and the comments of the delegates to the author of the proposal. If the proposal has been accepted, the author should publish the full description of the mineral in a recognised scientific journal within a period of two years. If not published within that time, the approved but unpublished mineral is invalidated.
In case of adverse vote, the author may introduce a new file taking into account the objections and remarks of the members of the Commission. The same procedure is then followed.
So long as the description of the mineral has not been published, the author may neither mention the name of the new species nor distribute any samples of it. In order to avoid that some researchers waste their time studying a mineral which they suppose to be new but which had already been described by a colleague and validated by the CNMMN but not published yet, the Commission regularly publishes, in the Canadian Mineralogist , a list of minerals recently approved by the IMA. These files comprise the registration number at the IMA, the chemical formula, a summary of the physical, crystallographic and optical properties of the mineral, without, however, mentioning its name, the name of the author(s), nor indicating the geographical location of the finding.
The procedure of the approval of new minerals as elaborated by the CNMMN of the IMA, is the result of the experience and competence of mineralogists of the entire international scientific community. It can, therefore, fully guarantee the good quality of the mineralogical nomenclature.
Donnay, G. and Fleischer, M. ( 1970 ): Suggested outline for new mineral descriptions American Mineralogist, 55, 1017-1019.
Dunn, P.J. and Mandarino, J.A. ( 1988 ): The Commission on New Minerals and Mineral Names of the International Mineralogical Association; its history, purpose and general practice, Mineralogical Record, 19, 319-323.
Fleischer, M. ( 1970 ): Procedures of the International Mineralogical Association Commission on New Minerals and Mineral Names, American Mineralogist, 55, 1016-1017.
Hey, M.H., Guillemin, C., Permingeat, F. and de Roever, J.P. ( 1961 ): Sur la nomenclature Minéralogique. Décisions de la Commission des Nouveaux Minéraux et des Noms de Minéraux de líAssociation Internationale de Minéralogie. Bulletin de la Société française de Minéralogie et de Cristallographie, 84, 96-105.
Mandarino, J.A., Nickel, E.H. and Cesbron, F. ( 1984 ): Rules of procedure of the Commission on New Mineral Names, International Mineralogical Association. American Mineralogist, 69, 563-564.
Nickel, E.H. and Mandarino, J.A. ( 1987 ): Procedures involving the I.M.A. Commission on New Minerals and Mineral Names and guidelines on mineral nomenclature. American Mineralogist, 72, 1031-1042.
Nickel, E. ( 1996 ): The I.M.A. Commission on New Minerals and Mineral Names: Procedures and guidelines on mineral nomenclature, 1997. Unpublished proposition, 12 pp.