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GEOREF RECORD

Krasnoite, the fluorophosphate analogue of perhamite, from the Huber open pit, Czech Republic and the Silver Coin Mine, Nevada, USA

S. J. Mills, J. Sejkora, A. R. Kampf, I. E. Grey, T. J. Bastow, N. A. Ball, P. M. Adams, M. Raudsepp and M. A. Cooper
Krasnoite, the fluorophosphate analogue of perhamite, from the Huber open pit, Czech Republic and the Silver Coin Mine, Nevada, USA
Mineralogical Magazine (June 2012) 76 (3): 625-634

Abstract

Krasnoite is a new mineral (IMA2011-040) from the Huber open pit, Krasno ore district, Czech Republic and the Silver Coin mine, Nevada, USA. Krasnoite is the fluorophosphate analogue of perhamite. Krasnoite occurs as compact to finely crystalline aggregates, balls and rosette-like clusters up to 1 mm across. Individual crystals are platy, show a hexagonal outline and can reach 0.1 mm on edge at Krasno and 0.4 mm at Silver Coin. At both localities, krasnoite occurs very late in phosphaterich paragenetic sequences. Krasnoite crystals are partly transparent with a typically pearly lustre, but can also appear greasy (Krasno) or dull (Silver Coin). The streak is white and the hardness is 5 on the Mohs scale. Crystals are brittle, have an irregular fracture, one imperfect cleavage on {001} and are not fluorescent under SW and LW ultraviolet light. Penetration twinning {001} is common. The density for both Krasno and Silver Coin material is 2.48(4) g cm (super -3) , measured by the sink-float method in an aqueous solution of sodium polytungstate. The calculated density is 2.476 g cm (super -3) (Krasno). Krasnoite crystals are uniaxial (+), with omega =1.548(2) and epsilon =1.549(2) (Krasno) and omega =1.541(1) and epsilon =1.543(1) (Silver Coin). The simplified formula of krasnoite is: Ca (sub 3) Al (sub 7.7) Si (sub 3) P (sub 4) O (sub 23.5) (OH) (sub 12.1) F (sub 2) .8H (sub 2) O. Krasnoite is trigonal, space group P3im1, with a=6.9956(4), c=20.200(2) Aa, V=856.09(9) Aa (super 3) and Z=3. Raman and infrared spectroscopy, coupled with magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectrometry, confirmed the presence of PO (sub 3) F, PO (sub 4) , SiO (sub 4) , H (sub 2) O and OH in the crystal structure of krasnoite.


ISSN: 0026-461X
EISSN: 1471-8022
Coden: MNLMBB
Serial Title: Mineralogical Magazine
Serial Volume: 76
Serial Issue: 3
Title: Krasnoite, the fluorophosphate analogue of perhamite, from the Huber open pit, Czech Republic and the Silver Coin Mine, Nevada, USA
Affiliation: Museum Victoria, Geosciences, Melbourne, Victoria, Australia
Pages: 625-634
Published: 201206
Text Language: English
Publisher: Mineralogical Society, London, United Kingdom
References: 18
Accession Number: 2012-092173
Categories: Mineralogy of non-silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables
N40°31'00" - N42°00'00", W119°20'60" - W117°00'00"
N50°07'21" - N50°07'22", E12°47'30" - E12°48'00"
Secondary Affiliation: National Museum Prague, CZE, Czech RepublicNatural History Museum of Los Angeles County, USA, United StatesCSIRO Process Science and Engineering, AUS, AustraliaUniversity of Manitoba, CAN, CanadaUniversity of British Columbia, CAN, Canada
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, Mineralogical Society of Great Britain and Ireland. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201248
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