Torshab Mine Stone

DONNA L. WHITNEY1,* AND BERNARD W. EVANS2
1Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, U.S.A.
2Department of Earth and Space Sciences, Box 351310, University of Washington, Seattle, Washington 98185, U.S.A.
Nearly 30 years have elapsed since Kretz (1983) provided
the mineralogical community with a systematized list of abbre-
viations for rock-forming minerals and mineral components. Its
logic and simplicity have led to broad acceptance among authors
and editors who were eager to adopt a widely recognized set of
mineral symbols to save space in text, tables, and figures.
Few of the nearly 5000 known mineral species occur in
nature with a frequency sufficient to earn repeated mention in
the geoscience literature and thus qualify for the designation
“rock-forming mineral,” but a reasonable selection of the most
common and useful rock-forming minerals likely numbers in
the several hundreds. The original list by Kretz (1983) contained
abbreviations for 193 of these.
We propose an expansion to the list initiated by Kretz (1983)
(see next page). Modest expansions and revisions were made by
Spear (1993), Holland and Powell (1998), the Mineralogical As-
sociation of Canada, and Siivola and Schmid (2007). Our revised
list of abbreviations has 371 entries. Significant numbers of the
new entries are the result of three decades of research in high- and
ultrahigh-pressure metamorphic terrains, the explicit inclusion of
Mg and Fe end-members of solid-solution series (as in the amphi-
boles), recent work on extraterrestrial samples, and the increased
relevance to petrology of numerous accessory minerals.
The two systems of abbreviations currently most in use—
Kretz (1983), including modifications; and Holland and Powell
(1998)—differ in terms of style and concept. Kretz abbreviations
are 2–3 letters and use uppercase first letters for minerals and
lower case letters throughout for mineral components (e.g., the
almandine component of garnet); the Holland and Powell sys-
tem varies from 1–5 letters and uses lowercase throughout. The
Kretz system provides abbreviations for selected intermediates
in solid-solution mineral series. The Holland and Powell system
is restricted to abbreviations for end-members for which there
are available thermodynamic data that have been included in the
Holland and Powell database. The two systems have the same
abbreviations for some minerals (other than capitalization), but
in many cases use different symbols for the same mineral, for
example, “Crn” (Kretz) and “cor” (H&P).

The selection of minerals to include in a list of abbreviations
is subjective, but we have tried to err on the side of being inclu-
sive, listing some minerals for which the status is questionable
according to the International Mineralogical Association. For
example, we accommodate alternative choices such as titanite
(Ttn) and sphene (Spn); hypersthene (Hyp), enstatite (En), and
orthopyroxene (Opx); glaucophane (Gln), crossite (Crt), and
riebeckite (Rbk); and albite (Ab) and anorthite (An) as well as
plagioclase (Pl), recognizing that some petrologists have uses for
these mineral names. In addition, although our focus is on rock-
forming minerals, some hypothetical and/or synthetic phases are
included in our list, as well as an abbreviation for “liquid” (Liq).
We have also included some abbreviations for mineral groups,
e.g., aluminosilicates (Als, the Al2SiO5 polymorphs), and other
descriptive terms (e.g., opaque minerals). The choice of abbre-
viations attempts as much as possible to make the identity of the
mineral instantly obvious and unambiguous.
UPDATED LIST OF MINERAL ABBREVIATIONS
In this contribution, abbreviations from Kretz (with some
modifications) and new abbreviations are listed (Table 1, next
page). The following format was used for assigning abbrevia-
tions:
(1) The first letter is capitalized; the other letter(s) are lower
case, with the exception of Phase A, abbreviated as PhA.
(2) The first letter of the abbreviation is the first letter of the
mineral name; subsequent letters are selected from the mineral
name.
(3) Most abbreviations consist of 2 or 3 letters, but a 4-letter
abbreviation is used when the addition of F for ferro- or M for
magnesio- resulted in ambiguity in the 3-letter version (e.g.,
Mcar for magnesiocarpholite).
(4) Mineral abbreviations were selected so as not to corre-
spond to abbreviations for elements. Note that rule 4 was violated
by a few of the original Kretz abbreviations (Mo for molybdenite;
Ne for nepheline), so some original Kretz abbreviations have
been changed to follow this rule. Others have been modified to
avoid ambiguity with minerals added to the list.
ACKNOWLEDGMENT
We thank Marc Hirschmann and Howard Day for input on the updated ab-
breviation system.
REFERENCES CITED
Kretz, R. (1983) Symbols of rock-forming minerals. American Mineralogist, 68,
277–279.
Holland, T.J.B. and Powell, R. (1998) An internally-consistent thermodynamic
data set for phases of petrologic interest. Journal of Metamorphic Geology,
16, 309–343.
Siivola, J. and Schmid, R. (2007) Recommendations by the IUGS Subcommission
on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Web
version 01.02.07. (http://www.bgs.ac.uk/scmr/docs/papers/paper_12.pdf)
IUGS Commission on the Systematics in Petrology.
Spear, F.S. (1993) Metamorphic Phase Equilibria and Pressure-Temperature-Time
Paths. Monograph 1, Mineralogical Society of America, Chantilly, Virginia.
MANUSCRIPT RECEIVED AUGUST 11, 2009
MANUSCRIPT ACCEPTED AUGUST 13, 2009
MANUSCRIPT HANDLED BY BRYAN CHAKOUMAKOS





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