DOCSLIB.ORG

Serendibite from the Northwest Adirondack Lowlands, in Russell, New York, USA

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Serendibite from the Northwest Adirondack Lowlands, in Russell, New York, USA SHORT COMMUNICATIONS 133 (Me75-83), aluminous diopside, green amphibole, Acknowledgements. This work was supported by con- colourless spinel, large poikilitic blue tourmaline, tracts CNRS-INSU 89 DBT V-11 and DBT 96. and a little calcite. Tourmaline includes several minerals, especially clinopyroxene, spinel, and a References few small crystals of serendibite. Scattered grains of the latter in one crystal of tourmaline are in de Roever, W. F. and Kieft, C. (1976) Am. Mineral. optical continuity, suggesting that tourmaline is 61,332-3. Grew. E. S. (1983) Mineral. Mag. 47,401-3. a breakdown product after serendibite. The ser- -- (1988) Am. Mineral. 73,345-57. endibite is colourless to very light green. The Haslam, H. W. (1980) Mineral. Mag. 43,822-3. mineral is much less coloured than the prussian Huijsmans, J. P. P., Barton, M., and van Bergen, blue crystals in a calcsilicate rock associated with M. J. (1982) NeuesJahrb. Mineral. Abh. 143, 24%61. clintonite clinopyroxenites from Ianapera, in SW Hutcheon, I., Gunter, A. E. and Lecheminant, A. N. Madagascar (Nicollet, 1988, 1990). The Ihosy ser- (1977) Can. Mineral. 15,108-12. endibite has low birefringence and fine polysyn- Lee, S. M. and Holdaway, M. J. (1977) Geophys. thetic twinning. It may be mistaken for Monogr. 20, 7%94. sapphirine, but it is distinguishable from the latter Lonker, S. W. (1988) Contrib. Mineral. Petrol. 98, by a larger extinction angle and by its occurrence 502-16. M6gerlin, N. (1968) C.R. Sere. GOol. Madagascar, 67-9. in calcic rocks. The ferromagnesian minerals in Nicollet, C. (1985) PrOcambr. Res. 28,175-85. the rock are magnesium rich. Tourmaline (Table -- (1988) Thbse d'Etat. Clermont Fd, 350pp. 1) is a magnesian uvite and the XMg ratio of the -- (1990) In Granulites and Crustal Dtfferentiation spinel is greater than 0.9. Hornblende and clino- (Vielzeuf, D. and Vidal, P., eds.), Kluwer Academic pyroxene are close to their Mg end-members publishers, in press. (XMg~0.97). The Fe-Mg partitioning between Semroud, B., Fabri6s, J., and Conqudr6, F. (1976) Bull. tourmaline and serendibite (Kd) is ~0.4 as in the Soc. fr. Mineral. Cristallogr. 99, 58-60. more iron rich pair from Ianapera; it is lower than van Bergen, M. 1. (1980) Mineral. Mag. 43,651-8. the Ka of coexisting tourmaline and serendibite von Knorring, O. V., Sahama, T. G., and Lehtinen, M. (1969) Bull. Geol. Soc. Finland, 41,79-84. from Melville Peninsula, Canada (Kd=0.61: Hutcheon et al., 1977). The P-T conditions of the crystallization of this [Manuscript received 2 June 1989; rock are similar to those estimated for the neigh- revised 13 July 1989] bouring seven-phase anatectic gneisses (Nicollet, 1988). Copyright the Mineralogical Society K EY W o RD S: grandidierite, serendibite, tourmaline, Ihosy, Madagascar, metamorphism. DOpartement de GOologie, UA 10, 5 Rue Kessler, Clermont Fd, 63038, France CHRISTIANNICOLLET MINERALOGICAL MAGAZINE, MARCH 1990, VOL. 54, PP. 13~-136 Serendibite from the northwest Adirondack Lowlands, in Russell, New York, USA SERENDIBITE, to a first approximation, Ca2(Mg, paper we report a new occurrence from the north- FeZ+)3(AI,Fe3+)4.sB1.5Si3020, has been reported west Adirondacks Lowlands. This occurrence has from about eight localities worldwide (Deer et al., many mineralogical and chemical features in com- 1978; Nicollet, 1988), including Johnsburg, New mon with the serendibite-diopside rocks in the York, in the southern Adirondack Highlands Johnsburg deposit, although located 130kin dis- (Larsen and Schaller, 1932; Grew et al., in press). tant. It is a mineral of high-temperature calc-silicate Serendibite occurs in core from hole 1872 skarns, mostly in the granulite-facies. In this drilled by St. Joe Resources Company (presently 134 SHORT COMMUNICATIONS Zinc Corporation of America) near Cassidy of scapolite. Fresh scapolite in grains ~<lmm Road, 350m south of Town Line Road, town of across occurs sparingly in and between diopside Russell, NY (44~ 75~ The drill hole or calcite and serendibite. Grandidierite, spinel, penetrated calc-silicate rocks and marbles typical and phlogopite occur in trace amounts within ser- of the northwest Adirondack Lowlands (e.g. endibite and appear to have formed from serendi- Bohlen et al., 1985). A summary of the core log bite breakdown. Tourmaline forms irregular, to 40 m is as follows (compositional layering inter- poikilitic patches around serendibite and in sected at high angle by the vertical core). places, margins around apatite enclosed in seren- 0-6m: Overburden. dibite. A mineral tentatively identified as sinhalite 6--8.5m: Biotite-diopside calc-silicate granu- occurs with spinel in serendibite. lites (e.g. at 7m, plagioclase-biotite-titanite- Textures suggest a 3-stage history for the seren- hornblende-diopside) dibite-diopside rock: (1) primary serendibite- 8.5-30 m: Diopside granulite with disseminated diopside_+scapolite-apatite assemblages; (2) cm-sized books of phlogopite, alternating with secondary assemblages with grandidierite, tour- amphibole-phlogopite rock at 16.8m, serendibi- maline, pargasite, spinel and/or phlogopite which te-diopside rock at 17.7m, and finely layered could have formed by reactions such as serendi- quartz-rich diopside-K-feldspar-titanite granu- bite + diopside + Na20 +.K20 + H20 + CO2 lite at 22-25 m. = grandidierite + pargasite + calcite + B203 (see 30-37.5m: Dolomite-calcite marble with ser- Grew et al., in press); and (3) alteration to fine- pentine (after forsterite?), minor spinel and phlo- grained phyllosilicates. The stage 2 minerals, gopite. notably grandidierite, are also characteristic of 37.5-40 m: Diopside-rich granulite. the Johnsburg serendibite-diopside rocks and The serendibite-diopside rock occurs over an thus we infer that a second high-temperature interval of 13-20cm (largest core fragment is 5cm event affected the Russell locality. Conditions of long). Recovery of the core was not complete and formation of the primary serendibite-diopside we are not able to fully characterise the layering assemblage could be 660-750 ~ and 6.7-7.4 kbar, in this section of the core. The closest rocks to values estimated at nearby localities (maps of the serendibite-diopside rock are diopside granu- Bohlen et al., 1985; Edwards and Essene's, 1988, lite with phlogopite books at 0.6m below and 700~ isotherm passes close to the locality), and amphibole-phlogopite rock at 0.9m above. The consistent with conditions inferred for serendibite latter is a relatively coarse intergrowth of phlogo- at other localities (Grew et al., in press). The core pite and calcic clinoamphibole in which diopside was drilled about 1 km northwest of Buddington's occurs sporadically, mostly included in the amphi- (1963) isograd marking the northern limit for bole. orthopyroxene in amphibolite, implying near gra- Important constituents of the serendibite-diop- nulite-facies conditions for serendibite at Russell, side rock are apatite, calcite, pargasite, and that is, somewhat lower temperatures than the secondary phyllosilicates resembling sericite and clearly granulite-facies Johnsburg deposit. chlorite, while scapolite, tourmaline, grandidier- Serendibite and associated minerals (1-2 grains ite, phlogopite, sulfide, sinhalite (?), and spinel each) were analysed with a wavelength-dispersive are rare. Serendibite is deep blue in hand speci- MAC 400s electron microprobe at the University men, while in thin section it forms pale-blue poly- of Maine (procedure of Yates and Howd, 1988) synthetically twinned grains up to I cm across with (Table 1). Assuming that the boron content is highly irregular outlines. Preferred orientation of similar to the values measured in the Johnsburg the grains is implied by parallelism of the twin serendibite (Grew et al., in press), analytical totals lamellae from grain to grain. Serendibite is partly for serendibite are reasonable and the formulae replaced by a birefringent material in which traces approach Ca2(Mg, Fe)3AI4.sBI.sSi3020 . Compo- of the twinning lamallae are preserved. A similar sitions of the two analysed grains can be related material replaces serendibite at Johnsburg (Grew by the Tschermaks substitution (Mg,Fe)+ Si = 2 et al., in press). Diopside occurs as inclusions in A1. Compared to serendibite from most other serendibite and as a granular matrix (grains localities (Deer et al., 1978); Nicollet, 1988), the mostly ~<0.5cm) to it. Patches and overgrowths Russell serendibites are magnesian and sodian, of pargasite are locally developed in and around but less so than the Johnsburg serendibites. Incor- diopside, most commonly along contacts with ser- poration of Na in the Russell and Johnsburg ser- endibite. Apatite is relatively coarse-grained endibites appears to be through the substitution (~<0.5cm). Larger calcite grains (1-4mm) are Na + Si = Ca + A1, which is characteristic of the mantled and penetrated by a phyllosilicate; these related minerals aenigmatite and rh6nite (Deer intergrowths may have resulted from alteration et al., 1978). Diopside compositions are also SHORT COMMUNICATIONS 135 Table 1. Compositions of minerals in the serendibite-diopside rock from Russell, N.Y. Mineral Serendibite Diopside Pargasite Scapolitr Grandidicrile Grain ] 2 1 2 Weight Pcrcenl SiO2 24.05 25.35 52.09 53.63 4310 46.73 20.81 TiO2 0.02 0.04 0.06 0.07 030 nd. .03 A1203 35.76 34.04 4.58 3.35 16.69 26.41 52.03 FeO 1.94 2.10 1.07 1.09 2.09 0.17 1.14 MnO 0.05 0.09 0.16 0.12 0.01 nd. 0.06 MgO 15.34 15.49 16.84 17.51 18.94 nd. 13.08 Ca(3 14.22 14.39 23.93 23.65 12.75 16.31 0,07 Na20 0.50 0.63 0.40 0.54 2.74 4.10 0.01 K20 0.00 0.00 0.02 0.04 1.40 0.16 0.05 CI nd. nd. nd. nd. nd. 0.50 nd. SO?,. nd.
Load more

Recommended publications
  • The New IMA List of Gem Materials – a Work in Progress – Updated: July 2018
    The New IMA List of Gem Materials – A Work in Progress – Updated: July 2018 In the following pages of this document a comprehensive list of gem materials is presented. The list is distributed (for terms and conditions see below) via the web site of the Commission on Gem Materials of the International Mineralogical Association. The list will be updated on a regular basis. Mineral names and formulae are from the IMA List of Minerals: http://nrmima.nrm.se//IMA_Master_List_%282016-07%29.pdf. Where there is a discrepancy the IMA List of Minerals will take precedence. Explanation of column headings: IMA status: A = approved (it applies to minerals approved after the establishment of the IMA in 1958); G = grandfathered (it applies to minerals discovered before the birth of IMA, and generally considered as valid species); Rd = redefined (it applies to existing minerals which were redefined during the IMA era); Rn = renamed (it applies to existing minerals which were renamed during the IMA era); Q = questionable (it applies to poorly characterized minerals, whose validity could be doubtful). Gem material name: minerals are normal text; non-minerals are bold; rocks are all caps; organics and glasses are italicized. Caveat (IMPORTANT): inevitably there will be mistakes in a list of this type. We will be grateful to all those who will point out errors of any kind, including typos. Please email your corrections to [email protected]. Acknowledgments: The following persons, listed in alphabetic order, gave their contribution to the building and the update of the IMA List of Minerals: Vladimir Bermanec, Emmanuel Fritsch, Lee A.
    [Show full text]
  • Optical Properties of Common Rock-Forming Minerals
    AppendixA __________ Optical Properties of Common Rock-Forming Minerals 325 Optical Properties of Common Rock-Forming Minerals J. B. Lyons, S. A. Morse, and R. E. Stoiber Distinguishing Characteristics Chemical XI. System and Indices Birefringence "Characteristically parallel, but Mineral Composition Best Cleavage Sign,2V and Relief and Color see Fig. 13-3. A. High Positive Relief Zircon ZrSiO. Tet. (+) 111=1.940 High biref. Small euhedral grains show (.055) parallel" extinction; may cause pleochroic haloes if enclosed in other minerals Sphene CaTiSiOs Mon. (110) (+) 30-50 13=1.895 High biref. Wedge-shaped grains; may (Titanite) to 1.935 (0.108-.135) show (110) cleavage or (100) Often or (221) parting; ZI\c=51 0; brownish in very high relief; r>v extreme. color CtJI\) 0) Gamet AsB2(SiO.la where Iso. High Grandite often Very pale pink commonest A = R2+ and B = RS + 1.7-1.9 weakly color; inclusions common. birefracting. Indices vary widely with composition. Crystals often euhedraL Uvarovite green, very rare. Staurolite H2FeAI.Si2O'2 Orth. (010) (+) 2V = 87 13=1.750 Low biref. Pleochroic colorless to golden (approximately) (.012) yellow; one good cleavage; twins cruciform or oblique; metamorphic. Olivine Series Mg2SiO. Orth. (+) 2V=85 13=1.651 High biref. Colorless (Fo) to yellow or pale to to (.035) brown (Fa); high relief. Fe2SiO. Orth. (-) 2V=47 13=1.865 High biref. Shagreen (mottled) surface; (.051) often cracked and altered to %II - serpentine. Poor (010) and (100) cleavages. Extinction par- ~ ~ alleL" l~4~ Tourmaline Na(Mg,Fe,Mn,Li,Alk Hex. (-) 111=1.636 Mod. biref.
    [Show full text]
  • Sadanagaite and Magnesio.Sadanagaite, New Silica-Poor Members of Calcic Amphibole from Japan
    American Mineralogist, Volume 69, pages 465471, 19E4 Sadanagaiteand magnesio.sadanagaite,new silica-poor membersof calcic amphibole from Japan Hrppnxo Sntrraezerr Geological Institute, Faculty of Science University of Tolcyo, Hongo, Tolcyo l13, Japan Mrcnrerr Buuxor Department of Mineralogy, The University Museum University of Tolcyo, Hongo, Tolcyo 113, Japan nxo Tonnu Ozewe Mineralogical Institute, Faculty of Science University of Tolcyo, Hongo, Tolcyo ll3, Japan Abstract Sadanagaite,(K,Na)CazGe2*,Mg,Al,Fe3*,Ti)r[(Si,AlhO22(OH)2] where Fe2* = Mg, Al = Fe3* and Si < 5.5, and its Mg-rich analogue,magnesio-sadanagaite Fe2+ < Mg, are extremely SiO2-poor new amphiboles, which require the compositional extension of the edenite-pargasiteseries, and amending of the classification and nomenclature of amphi- boles (Leake, 1978). Theseare monoclinic,C2, Cm or Cllm; a = 9.922(10),b : 1E.03(2),c : 5.352(9)4,B: 105.30(10f,Z = 2 for sadanagaitewith Si - 5.0, and a : 9.964(2),D : 18.008(3),c : 5.354(2)4,B = 105.55(2)",2= 2 for magnesio-sadanagaitewith Si:5.0. The strongest lines in the X-ray powder pattern for magnesio-sadanagaiteare: 8.48(80)(ll0), 3.39(40Xl3l), 3.28(100X240),3.15(70)(3r0), 2.951(50X22r),2.823(30)(330), 2.766(45)(33r), 2.707(60Xl5l),2.594(35X061),2.162(55)(261),1.654(30X461), thesebeing similar to thoseof X-ray powder patterns of SiO2-poorcalcic amphiboles, especially kaersutite. Both specieshave very similar physical properties, and are dark brown to black with a vitreousluster. Streak very light brown.
    [Show full text]
  • Occurrences of Grandidierite, Serendibite and Tourmaline Near Ihosy, Southern Madagascar
    SHORT COMMUNICATIONS 131 tine, lavendulan, schoepite, vandendriesscheite, Collins, J. H. (1881) Catalogue of the Minerals in the kahlerite and metakahlerite are confirmed for the Museum of the Royal Institution of Cornwall, 2, 32. first time from the British Isles. Foshag, W. F. (1924)Am. Mineral. 9, 30-1. Goldsmith (1877) Proc. Acad. Nat. Sci. Philadelphia, Acknowledgements. For X-ray diffraction work, the 192. authors are grateful to the late Dr R. J. Davis of the Guillemin, C. (1956) Bull. Soc. franc. Min. Crist. 79, British Museum (Natural History), to Dr T. M. Seward, 7-95. then of the Geology Department, University of Man- Harrison, R. K., Tresham, A. E., Young, B. R. and chester, to Dr D. Rushton, then of the Manchester Lawson, R. I. (1975) Bull. Geol. Survey Great Britain, Museum, and to the staff of the Royal Scottish Museum. 52, 1-26. We thank Ian Brough of the Metallurgy Department, Macpherson, H. G. and Livingstone, A. (1982) Gloss- University of Manchester and U.M.I.S.T. for scanning ary of Scottish Mineral Species 1981. Scottish Journal electron microscope analysis. For their help in field work of Geology. we thank Dr George Ryback, Dr T. M. Seward and Miller, J. M. and Taylor, K. (1966) Bull. Geol. Survey Mr T. G. P. Ziemba. Great Britain, 25, 1-8. Weisbach, A. (1871)Neues Jahrb. Min. 869-70. -- (1877) Ibid., 1. References [Manuscript received 25 January 1989; Breithaupt, J. F. A. (1837)J. prakt. Chem. 10,505. revised 18 April 1989] Clark, A. M., Couper, A. G., Embrey, P. G.
    [Show full text]
  • Khmaralite, a New Beryllium-Bearing Mineral Related to Sapphirine: a Superstructure Resulting from Partial Ordering of Be, Al, and Si on Tetrahedral Sites
    American Mineralogist, Volume 84, pages 1650–1660, 1999 Khmaralite, a new beryllium-bearing mineral related to sapphirine: A superstructure resulting from partial ordering of Be, Al, and Si on tetrahedral sites JACQUES BARBIER,1,* EDWARD S. GREW,2 PAULUS B. MOORE,3 AND SHU-CHUN SU4 1Department of Chemistry, McMaster University, Hamilton, Ontario, L8S 4M1 Canada 2Department of Geological Sciences, University of Maine 5790 Bryand Center Orono, Maine 04469, U.S.A. 3P.O. Box 703, Warwick, New York,10990, U.S.A. 4Hercules Research Center, 500 Hercules Road, Wilmington, Delaware 19808, U.S.A. ABSTRACT 3+ 2+ Khmaralite, Ca0.04Mg5.46Fe 0.12Fe 1.87Al14.26Be1.43B0.02Si4.80O40, is a new mineral closely related to sapphirine from Khmara Bay, Enderby Land, Antarctica. It occurs in a pegmatite metamorphosed at T ≥ 820 °C, P ≥ 10 kbar. The minerals surinamite, musgravite, and sillimanite associated with khmaralite at Casey Bay saturate it in BeO, and thus its BeO content could be close to the maximum possible. Optically, khmaralite is biaxial (–); at λ = 589 nm, α = 1.725(2), β = 1.740(2), γ = 1.741(2), 2Vmeas = 34.4 (1.8)°, v > r strong, and β b. The weak superstructure reported using electron diffraction has been confirmed by single-crystal X-ray diffraction. The superstructure corresponds to a doubling of the a axis in monoclinic sapphirine-2M (P21/c setting) with the following unit-cell parameters: a = 3 19.800(1), b = 14.371(1), c = 11.254(1) Å, β = 125.53(1)°, Z = 4, Dcalc = 3.61 g/cm .
    [Show full text]
  • Spring 2002 Gems & Gemology
    Spring 2002 VOLUME 38, NO. 1 EDITORIAL 1 Richard T. Liddicoat: Celebrating 50 Years of Leadership William E. Boyajian FEATURE ARTICLES 2 The Ultimate Gemologist: A Tribute to Richard T. Liddicoat Dona M. Dirlam, James E. Shigley, and Stuart D. Overlin A look at the extraordinary career of Richard Liddicoat. 14 Portable Instruments and Tips on Practical Gemology in the Field Edward W. Boehm An essential guide to the use of portable instruments when purchasing gems. 28 Liddicoatite Tourmaline from Anjanabonoina, Madagascar Dona M. Dirlam, Brendan M. Laurs, Federico Pezzotta, and William B. (Skip) Simmons pg. 3 Explores the world’s primary source of this remarkable calcium-rich lithium tourmaline, named in honor of Richard T. Liddicoat. 54 Star of the South: A Historic 128 ct Diamond Christopher P. Smith and George Bosshart A history and characterization of this famous diamond. NOTES AND NEW TECHNIQUES 66 Identification of Yellow Cultured Pearls from the Black-Lipped Oyster Pinctada Margaritifera Shane Elen How absorption features can establish the origin of these cultured pearls. pg. 22 73 Serendibite from Sri Lanka Karl Schmetzer, George Bosshart, Heinz-Jürgen Bernhardt, Edward J. Gübelin, and Christopher P. Smith A characterization of this rare gem material from Sri Lanka. REGULAR FEATURES 80 Gem Trade Lab Notes • Color grade vs. value for fancy-color diamonds • Diamond with eclogitic inclusions • Diamond with a large void • Genthelvite: A second occurrence • Jadeite carving: Assembled, dyed, and impregnated • Coated natural pearls •
    [Show full text]
  • Pargasites in Lherzolite and Websterite Inclusions from Itinome-Gata, Japan
    J. Japan. Assoc. Min. Petr. Econ. Geol. 68, 303-310, 1973 PARGASITES IN LHERZOLITE AND WEBSTERITE INCLUSIONS FROM ITINOME-GATA, JAPAN KEN-ICHIRO AOKI and IKUKO SHIBA Institute of Mineralogy, Petrology and Economic Geology, Tohoku University, Sendai, Japan Pargasite occupies up to 4 volume per cent of lherzolite inclusions and up to 8 per cent of websterite inclusions. It occurs as discrete primary crystals and as interstitial grains among other minerals averaging less than 2 volume per cent. New analyses are presented for six representative pargasites. They are characterized by high Cr2O2 and wide variation of K2O and Mg/(Mg+Fe) ratio. The following origin of the pargasites is hypothsized from the mineralogy and chemist ry of the host rocks. Original garnet lherzolite and websterite were located at a depth of up to 50 to 75km. During upward transport, to 25km deep in the uppermost part of the mantle, the garnet was finally transformed to olivine+plagioclase+spinel and both orthopyroxene and clinopyroxene were recrystallized toward a relatively rich Tschermak's molecule. Jadeite and Tschermak's components separated from pyroxenes and silica liberated from the breakdown of garnet produced plagioclase, pargasite and orthopyroxene. However, minor newly-formed minerals were not always in equilibrium with major consti tuents. It is demonstrated that the lherzolite mantle just below the M-discontinuity contains only up to 0.04 per cent water. INTRODUCTION (Kushiro, 1970). Because the former has been found only in kimberlite diatremes at Oxburgh (1964) suggested that am Buell Park, Arizona (Aoki, et al., 1972), it phibole would be stable in an upper mantle of peridotite composition, playing a very is thought to be a rare occurrence in the important role in basaltic magma genera mantle.
    [Show full text]
  • Cl-Rich Amphiboles As Record for Hydrothermal Processes at Very
    Cl-rich amphiboles as record for hydrothermal processes at very high temperatures in the deep oceanic crust: brine/rock interaction experiments and investigation on natural rocks Von der Naturwissenschaftlichen Fakultät der Gottfried Wilhelm Leibniz Universität Hannover zur Erlangung des Grades Doktorin der Naturwissenschaften (Dr. rer. nat.) genehmigte Dissertation von Adriana Miriam Currin Sala, M. Sc (Niederlande) 2018 Referent: Prof. Dr. rer. nat. Jürgen Koepke Korreferenten: Prof. Dr. rer. nat. Wolfgang Bach Prof. Dr. sci. nat. Ulrich Heimhofer Tag der Promotion: 15.11.2018 2 Abstract Interactions between rock and high temperature seawater-derived fluids are recorded in hydrothermal veins and dykelets that cross-cut layered olivine gabbros deep in the plutonic section of the Samail Ophiolite, Wadi Wariyah, Sultanate of Oman. Here we present a study – using petrographic, microanalytical, isotopic, and structural methods – of amphiboles found in the aforementioned veins and dykelets, which show a conspicuous compositional variation from high-Ti magnesiohastingsite and pargasite via magnesiohornblende and edenite, to Cl-rich ferropargasite and hastingsite (with up to 5.4 wt% Cl) and actinolite. These minerals record a wide range of formation conditions from magmatic to hydrothermal at varying water/rock ratios and salinities, while the formation of super Cl-rich amphibole suggests the occurrence of phase separation, and 87Sr/86Sr and stable δ18O isotope analyses confirm the influence of a hydrothermal fluid in a rock-dominated environment. A parallel experimental study was conducted at hydrothermal (500 – 750 °C) and magmatic (900 °C) conditions at pressures of 2 kbar, and fO2 close to NNO, with an amphibole-containing natural olivine gabbro and saline fluid (6, 20 and 50 wt% NaCl).
    [Show full text]
  • The First Transparent Faceted Grandidierite, from Sri Lanka
    THE FIRST TRANSPARENT FACETED GRANDIDIERITE, FROM SRI LANKA By Karl Schmetzer, Murray Burford, Lore Kiefert, and Heinz-Jürgen Bernhardt different localities is described as blue, greenish blue, blue-green, and bluish green. Gemological, chemical, and spectroscopic proper- The Kolonne area of Sri Lanka, which is located ties are presented for the first known transparent approximately 8 km south-southeast of Rakwana, faceted grandidierite. This jewelry-quality 0.29 ct near Ratnapura, has become known for some rare stone was fashioned from rough reportedly found in the Kolonne area of Sri Lanka. The greenish blue gem materials such as sapphirine (Harding and Zoysa, borosilicate has refractive indices of 1.583 to 1.622, 1990), olivine with a high iron content (Burford and which correlate to a low iron content of 1.71 wt.% Gunasekera, 2000), and—most recently—the Ca-Mg- FeO and readily separate it from the gem material Al borosilicate serendibite (Schmetzer et al., 2002). In closest in properties, lazulite. 2000 while in Ratnapura, one of the authors (MB) purchased the grandidierite described in this article, reportedly from the Kolonne area, as an 0.85 ct crys- tal fragment. After faceting, the rough yielded a 0.29 randidierite, a magnesium-aluminum ct greenish blue transparent gemstone (figure 1). borosilicate, MgAl3BSiO9, is mentioned only The Sri Lankan seller offered the rough gem (on G rarely as a “possible” blue gemstone the basis of its color) as a “possible serendibite.” (Ostwald, 1964), although the existence of faceted The original flat, tabular crystal did not appear to be stones has been reported occasionally in the gemo- water worn.
    [Show full text]
  • A Specific Gravity Index for Minerats
    A SPECIFICGRAVITY INDEX FOR MINERATS c. A. MURSKyI ern R. M. THOMPSON, Un'fuersityof Bri.ti,sh Col,umb,in,Voncouver, Canad,a This work was undertaken in order to provide a practical, and as far as possible,a complete list of specific gravities of minerals. An accurate speciflc cravity determination can usually be made quickly and this information when combined with other physical properties commonly leads to rapid mineral identification. Early complete but now outdated specific gravity lists are those of Miers given in his mineralogy textbook (1902),and Spencer(M,i,n. Mag.,2!, pp. 382-865,I}ZZ). A more recent list by Hurlbut (Dana's Manuatr of M,i,neral,ogy,LgE2) is incomplete and others are limited to rock forming minerals,Trdger (Tabel,l,enntr-optischen Best'i,mmungd,er geste,i,nsb.ildend,en M,ineral,e, 1952) and Morey (Encycto- ped,iaof Cherni,cal,Technol,ogy, Vol. 12, 19b4). In his mineral identification tables, smith (rd,entifi,cati,onand. qual,itatioe cherai,cal,anal,ys'i,s of mineral,s,second edition, New york, 19bB) groups minerals on the basis of specificgravity but in each of the twelve groups the minerals are listed in order of decreasinghardness. The present work should not be regarded as an index of all known minerals as the specificgravities of many minerals are unknown or known only approximately and are omitted from the current list. The list, in order of increasing specific gravity, includes all minerals without regard to other physical properties or to chemical composition. The designation I or II after the name indicates that the mineral falls in the classesof minerals describedin Dana Systemof M'ineralogyEdition 7, volume I (Native elements, sulphides, oxides, etc.) or II (Halides, carbonates, etc.) (L944 and 1951).
    [Show full text]
  • Analyses of Rocks and Minerals
    UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director / rf Bulletin 878 ANALYSES OF ROCKS AND MINERALS FROM THE LABORATORY OF THE UNITED STATES GEOLOGICAL SURVEY 1914-36 TABULATED BY ROGER C. WELLS Chief Chemist UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1937 For sale by the Superintendent of Documents, Washington, D. C. ------ Price 15 cents V CONTENTS Page Introduction._____________________________________________________ 1 The elements and their relative abundance.__________________________ 3 Abbreviations used._______________________________________________ 5 Classification.___________________________________________________ 5 Analyses of igneous and crystalline rocks____-_________.._____________ 6 Alaska._____-_____-__________---_-_--___-____-_____-_________ 6 \ Central Alaska________________________________________ 6 Southeastern Alaska___________-_--________________________ 7 Arizona._________--____-_---_-------___-_--------_----_______ 8 Ajo district.-_--_.____---------______--_-_--__---_______ 8 Oatman district____________-___-_-________________________ 9 Miscellaneous rocks....-._...._-............_......_._.... 10 Arkansas.____________________________________________________ 11 Austria._____________________________________________________ 11 California.__,_______________--_-_----______-_-_-_-___________ 11 T ' Ivanpah quadrangle.____-_----__--_____----_--_--__.______ 11 Lassen Peak__________________ ___________________________ 12 Mount Whitney quadrangle________________________________
    [Show full text]
  • Spinel from Mogok, Myanmar—A Detailed Inclusion Study by Raman
    FEATURE ARTICLE Spinel from Mogok, Myanmar—A Detailed Inclusion Study by Raman Microspectroscopy and Scanning Electron Microscopy Myint Myat Phyo, Eva Bieler, Leander Franz, Walter Balmer and Michael S. Krzemnicki ABSTRACT: Mineral inclusions within 100 gem-quality spinels from both primary marble and secondary alluvial mining sites within Myanmar's Mogok Valley were analysed using Raman microspectroscopy and scanning electron microscopy (including backscattered-electron imaging and energy-dispersive spectroscopy). The samples ranged from pink to red, orangey pink to orangey red, and grey to purplish grey. We identified a number of inclusions that are reported here for the first time in Mogok spinel: amphibole (presumably pargasite), anatase, baddeleyite, boehmite, brucite, chlorite, clinohumite, clinopyroxene, diaspore, geikielite, goethite, halite, marcasite, molybdenite, periclase and pyrrhotite. We also found several minerals that were previously known as inclusions in Mogok spinel, including anhydrite, apatite, carbonates (calcite, dolomite and magnesite), chondrodite, elemental sulphur, graphite, iron oxides or iron hydroxides, phlogopite and zircon. We further differentiated the occurrence of inclusions in spinel from different mining sites in Mogok to assess whether these mineral assemblages can enhance our understanding of the geological origin of these gems and whether the inclusions can help separate Mogok spinels from those of other marble-related deposits worldwide. The Journal of Gemmology, 36(5), 2019, pp. 418–435, http://doi.org/10.15506/JoG.2019.36.5.418 © 2019 Gem-A (The Gemmological Association of Great Britain) ince ancient times, gem-quality spinel (ideally imperial jewels, two of which were later integrated into MgAl2O4) has been appreciated for its range British royal jewels (the Black Prince’s ‘Ruby’ and the of colour and often exceptional clarity, and Timur ‘Ruby’; see also Pardieu & Hughes 2008; Yavorskyy today spinel is the second most important and & Hughes 2010; Truong 2017).
    [Show full text]