AmericanMineralogist, Volume63, pages 930-937 , 1978

Abelsonite,.Greennickel porphyrin' a newmineral from the RiverFormation, Utah

CHnnI-rsMIlroN The GeorgeWashington Uniuersity, Washington, D'C' 20052 and tl.S. GeologicalSuruey, Reston, Virginia 22092

Eow,'rRPJ. DwonNlr IJ.S.Geological Suruey, Reston, Virginia 22092

PerntctnA. EsrnP-BnnNns U.S. DePartmentof EnergY . ltashington,D.C' 20545

Rosrnt B. FINxTI-ueN L/.5.Geological Suruey, Reston, Virginia 22092

Apoln Pessr Departmentof Geologyand Geophysics IJniu e r s i ty of Califu rnia, Be r keI e y, Cal ifu r nia 947 20

It'tP S uS,o'NP,'rt-trln R

Department of Geology, Florida Atlantic Uniuersity Boca Raton, Florida 33431

Abstract

has Abelsonite,a crystallinenickel porphyrin with the probablecomposition Ca,HsrNoNi, River beenfound in eight drill coresin or near the MahoganyZone oil shaleof the Green Formation in Uintah .County, Utah. Associatedauthigenic minerals include orthoclase' pyrite, quartz, dolomite, anaicime,and a K-Fe micaceousmineral. Abelsoniteoccurs as pink-purp.leto algregatisof platy crystals,as much as 3 mm long, that rangein color from to Oait ieddish-brown.The crystalsare very soft ((3 on Mohs scale)and havea semimetallic redor reddish- adamantineluster. Probabli cleavage is (1Tl).In transmittedlight the color is liquids and its brown, with intenseabsorption to .-.ddith-b.own.Its reactionwith high-index is triclinic, strong absorptionprevented determination of optical characteristics..Abelsonite = = 7'284'a ,pu.rlg.oupaspect P*, with celldimensions(Weissenberg),a 8'44,b: ll'12'c :90.53',B:ttZ"lS,,^y--79o34';volume6l3.8As,calculateddensity(forZ=l):1.459/ intensity' cme.The five strongestlines of the X-ray powder pattern (d value i-nA, relative (40) 012. indices)are 10.9(100) 010, 3.77 (80) itl, t.St 1iO; tOO,5.79 (40) 1T0,3.14 Ultraviolet,visible, and infraredspectra indicate that abelsoniteis a deoxophylloerythroetio- H' porphyrin,presumably a chlorophyllderivative. The mineralis namedin honorof Philip Abelson,President, Carnegie Institution of Washington' C. Trudell (Departmentof En- Introduction 1969by Lawrence Energy Researchcenter: Dor/Lnnc) Abelsonite,a nickel PorPhYrinwith a probable ergy/Larumie WesternOil ShaleCorporation compositionof CsrHs2N4Ni,was first obsirved in in a samplefrom the Cf,O3404X / 78 /09 I o-0930$02.oo 930 MILTON ET AL.: ABELSONITE 931

Tablel. Locationsof coreholesand abelsonite-bearingsamples in southeasternUinta Basin,Uintah County, Utah

V/elI No. Location Quadranele flor{h nf lin raa+\

IIVOSCO Sec J6 T 9SR20E Big Pack Mt. NE 2508.2- 2508.15

MDA/ Lr,nV Z >eC J) I vnnzIL Agency Drar,v NE 222.92- 222.93, 223, 223.5) - 223.59, 226.p, 229.77

rr ? .(aa 1ry T T3SR22 E BatesKnoll- 65.26, r8I.I9, l-87.35- r8I.37, 78L./+7, 782.17, 782.22, LgO.25, 19O.61, r%.7O, r9O.75 - r9O.9

d Sec35T]-JSB22E 86.05 - 86.l'0, 86.2 - 86.3, 196.3r, t95.9r, 20r.6 ' 6 Sec31T13SR22E iltl ro2.3 - \o2.5, 231.60- 231.62 | 7 Secl-dTI/+SR22E Pine Sprirg 15.07 - 15.rO, 15.8 - 45.83

'r 8 Sec26T13SR23E Cooper Carryon 98.61 - 98.68, rO2.18 - rO2.52

" 9 Sec6 T1-3SR2/-E Burnt Timber 160.26- a6o.27, 232.2, 25r.83, 253.O3- 253.2, 254.35, 251.11, test core (Table l, Wosco). He recordeda "tight at a depthof 2508ft.; this localityis about l6 miles verticalfracture from 2508.4to 2508.8ft. with black northwestof the other occurrences(core samples coatingsand occasionalfine pink-purplemetallic hereindesignated as DoElLERc), where samples were patches"not over3 mm in size(Trudell, 1970). The found at much shallowerdepths, less than 258 ft. secondobservation (Table l, No. 3) was also re- Until now, naturallyoccurring crystalline porphyrins portedby Trudell(personal communication, Novem- havenot beenrecognized, although Moore and Dun- ber 20, 1975)as "minute purplecrystalline masses." ning(1955) solvent-extracted nickel and iron porphy- Soonthereafter, Cassandra Sever (Don/Lnnc) noted rins from the eastward-extendingMahogany Ledge that abelsonitewas found in six other cores,which oil shale in Colorado; and Sugiharaand McGee arelisted in Tablel. (1957)isolated, by solventextraction, a nickelpor- Abelsonite(approved by the Commissionon New phyrin from Utah gilsonite.The NW-SE trending Minerals and Mineral Names,IMA) is namedin gilsoniteveins, as mappedby Cashion(1967), arc a honor of Philip H. Abelson,President of the Car- negieInstitution of Washingtonand editor of Sci- ence,a pioneerin organicgeochemistry. Specimens of type abelsonite(NMNH 143566)have been depos- ited in the National Museumof Natural Historv. Washington,D.C. Occurrenceand localities In the eight localities(Table l), all in Uintah County, northeasternUtah (Fig. I ), abelsoniteis presentas macroscopicallycrystallized aggregates of platy crystals.All the sampleswere found in or near the MahoganyZone, probably in the lower part (W.B. Cashion,U.S. GeologicalSurvey, personal communication,May ll, 1976).The Mahogany Zoneis the subsurfaceequivalent of the kerogen-rich 11f 11tr 10r 1F MahoganyLedge in the ParachuteCreek member of ffi GreenRrw Fumaion ffi.Abelson1e oeruence the Green River Formation.Pink platy abelsonite Fig. l. Map showingextent of GreenRiver Formationand area was foundin one sample(Wosco; the type locality) of abelsoniteoccurrences in northeasternUtah. 932 MILTON ET AL.: ABELSONITE

type locality to dark reddish-brown at the other oc- currences.The luster is semimetallicto adamantine. Abelsonite does not fluorescein long- or short-wave ultraviolet radiation. Determination of indices of refraction by the im- mersion method was impossiblebecause of the strong reddish-brown to reddish-black absorption and be- cause the mineral is rapidly attacked by diiodome- thane and other high-index liquids. Abelsonite is in- soluble in water and in dilute hydrochloric and nitric acids; it is soluble in benzeneand acetone. The mineral is very soft ((3 on Mohs scale)and easily deformed by pressure.Probable cleavageis Fig. 2. Aggregateof abelsonitecrystals from Dot/LEnc No. 6, (lTl). The density of abelsonite,1.45 g/cm3, was UintahCounty, Utah. Photomicrograph,60 X. computedusing the X-ray cellvolume (613.8 A3) and the mass-spectrometricmolecular weight (518), as- few kilometers northeast and east of the abelsonite suming one moleculeper unit cell. During an experi- localities. ment, a particle was observedto sink in dichlorome- Becauseof the rarity and small sizeof the abelso- thane(G : 1.33)and float in chloroform(G : 1.48); nite crystal aggregates,ranging from 30 micrometers the calculateddensity is within the rangeof the exper- to 3 mm (Fig. 2), and superficialresemblance to "iron imental observations. stains" or similar nondescript material, abelsonite may easily be overlooked in casual observation.Its Chemical analysis identification in at least seven of ten Doe/Lrnc Microprobe analysisof six separategrains of type cores,from test holesscattered over an area ofabout abelsoniteshowed a range in nickel content from ll 250 squaremiles, and in the Wosco core (from a test hole about 16miles northwestof the others),indicates that the mineral probably is presentin a fairly exten- sive area in the Green River Formation. The "black coatings," noted above by Trudell (shown in Figs. 3, 4, and 5), are a finely crystallized dark-brown micaceousaggregate, not noted in pre- vious Green River mineralogical investigations;its precisenature is not known. Preliminary study sug- gests a K-Fe mica-like mineral. Other identifiable authigenic minerals associatedwith abelsonite are albite and orthoclase (Figs. 3, 4, and 5), pyrite, quartz, dolomite, and analcime. The descriptivedata of this report, particularly the unit cell determination by Adolf Pabst, and the in- frared, visible, ultraviolet, and mass spectrometric studiesby P.A. Estep-Barnesand SusanPalmer, were made on the type material (Wosco). Identificationof abelsonitefrom the sevenDor,/Lrnc cores is based on comparison of their X-ray powder patterns and physicalproperties, ultraviolet and massspectra, and on the presenceof nickel as the only metal ion.

Physical properties Abelsonite (<3 occurs as small mm) aggregatesof Fig 3. Large (broken) crystalof abelsonite(a), with sheavesof thin translucent laths or plates (Fig. 2). Its color an authigenicmicaceous mineral (m), and orthoclasecrystals (o) variesfrom light "pink-purple" (Trudell, 1970)at the (Wosco). Scanningelectron micrograph, 160 X MILTON ET AL.: ABELSONITE 933 to l4 percent.Approximately l0 fragmentsfrom the other occurrenceswere observedby using a scanning electron microscope equipped with an energy-dis- persivesystem; the nickel contentwas estimatedto be about 10 weight percent. In addition to the nickel determination,carbon valuesof 40-50 weight percent were obtained by microprobe analysis on the type material. Nitrogen could not be determined and probably was below the level of detection for the microprobe system (-10 weight percent). No other elementswere detected.The intimate intergrowth of much of the abelsonitewith otherminerals (Figs. 3,4, and 5) and the limited quantity available(a few milli- grams) made attempts at more detailed chemical analysisimpractical.

X-ray crystallography Four fragmentsof type abelsonitewere examined by single-crystalX-ray diffraction methods.Only two of them yielded useful results.Altogether, no more than a few score of distinct identifiable diffraction spots extend to sindltr : 0.3. This limited range of Fig. 5 Unidentified micaceous mineral with orthoclase crystals "reflection," similar to that reported for a related (o) (Wosco) Scanningelectron micrograph, 600 X. compound, Ni-etioporphyrin (Crute, 1959;Fleischer, 1963), for which disorder has been postulated, is The lattice derived from Weissenbergdata is tri- probably also attributableto disorderor other crystal clinic with diffraction aspectP*. From measurements imoerfections. on a [0T] rotation pattern and the correlated0-, lst-, 2nd- and 3rd-layer equi-inclinationWeissenberg pat- terns, the reciprocal lattice constants(scaled to tr = I .54178A)were determinedand the direct latticecon- stants calculatedfrom these.The cell as reported in Table 2 is "reduced" in the sensethat a, b and c are the shortest non-coplanar translations; it is right- handed and conforms to "rule 6" of Crystal Data (Donnay et al., p. 2, 1963), "non-acute interedge anglesa and 8." This correspondsto Buerger'sType I crystal, orientation abc : XYZ (Buerger, 1963). The lattice dimensionsrefined by Dr. Daniel Ap- pleman by least-squaresanalysis of the powder data (indexed with the aid of single-crystalWeissenberg photographs) are listed in Table 2 for comparison with those derived from Weissenbergdata. The orientation of the translation lattice with re- spectto the outline of a typical lath is partly shown in Figure 6. The plane of the lath (or cleavage)( I I I ) has a calculatedd spacingof 3.76A. There are 2l lattice planeswith larger spacings.The axis of elongation,as observedon only two fragments,is [01], with iden- tity distanceca. l3.l8A. This is somewhatunusual, as plane of micaceouscrystals is generally Fig. 4. Abelsonite (a) with authigenic orthoclase (o) and the cleavage mlcaceousmineral(m) (Wosco). Scanningelectron micrograph, that of greatestspacing, and the longestaxis is ordi- 800x. narily normal or nearly normal to the cleavage. 934 MILTON ET AL.: ABELSONITE

Table 2. Cell constants of abelsonite Table 3. X-ray powderdiffraction data for type abelsonite (Wosco) fYm least squares refinment of Dwder data -vergsrglcq olseneal) a s./r1R 8.t08(21) f hkl, E (8)2) s(8) r b 11 .12 Lr,185(27 ) 010 10.91 r0,9 100 100 7.58 7.63 50 c n)A 7.299(!r) 110 6.41 6.85 5 ' 900r, 9oo5r(15 ) 001 6.65 6.63 30 r01 6.17 tt3o 45, 11/+oO8(12) | ,{ 011 7f34' 79o1903)' 111 v 6D.8 R3 110 5.73 5,79 /,0 011 5 5t ?5 020 5,16 The numberof parametersrequired to specifyall 11r 5.31 L20 1.90 t0 atomic positionsfar exceedsthe numberof observ- 021 1.36 1.)9 r0 able reflections,even if the crystalsshould contain 101 4.22 but a singletype of molecule.A full crystal-structure 111 determinationof abelsoniteis not possibleat this 021 1.09 time. 120 1.U7 2Ll Nevertheless,the meagercrystallographic data ob- 1.0' 2IO 3.8r tainedfor abelsonitedo givea basisfor somespecula- 200 3.79 tions about the structure.From latticedimensions 111 3 '76 3,77 80 alone,there being but one Ni per cell,it is easyto 220 3.11 show that distancesfrom a Ni atom to the nearest 2LO eightNi atomsare a 7.30,c 8.51, 8.66,and b QO [01] 02 3 .21 ll.l8A, eachtwo times,average 8.91A. In thestruc- 3 '2/' ture of nickeletioporphyrin-I (Fleischer, 1963), with 012 ? t? ),r1 10 a densityof 1.35g/cms, distances from a Ni atomto 2.60 5 2.29 5 the nearest8 Ni atomsarej.93A for four and 12.04A 2.27 5 for four, average9.984; the moleculesare nearly I) Indexed with the aid of sirgle-crystal Weissenberg photogrcphs. planarand arein a staggeredarrangement by 4, axes 2) Calculated fr@ singtecrystal Weiss$berg cel1 constdts (tatte Z). 3) I]1.59 m Deb_yescherrer powaler cmera. V-filtered CrK rediation with about3.lA betweenthe levelsof the molecules. (\ = 2.289624). No lnterml stddard. Intensities visully The moleculesin abelsonite,if parallelto (lTl), are estrlmted. staggeredin a lesssymmetrical manner with a greater distancebetween successive levels. The mesharea of (l I l) in abelsoniteis 162.8A',whereas that of (001) in nickeletioporphyrin-I is 213.4A2,suggesting that the moleculesin abelsonitemay departmore from planarity,which correlateswith the slightlygreater densityof abelsonite.The mineralsurely formed at depth under far greaterpressure than the synthetic material. Indexed X-ray powder diffraction data for type abelsonite(Wosco) are given in Table 3. Powder patternstaken of materialfrom the other localities werevirtually identical.

Ultraviolet-visible spectrophotometry,mass and infrared spectrometry Fig. 6. Idealized sketch of orientation relations in abelsonite. The (lTl ) surfacesare always buckled; the [0T] edge was observed Ex pe rimental p rocedure as a straight line on only one fragment, and transversesurfaces are uneven though there is a suggestion of faces parallel to this edge Small amounts of abelsonitecrystals were dis- and at a large angle to the cleavage. solvedin benzenein acetone,and UV-visiblespectra MILTON ET AL,: ABELSONITE 93s

FREQUENCy,cm-l equippedwith a direct probeinlet system.The probe 28,000 26,000 24,000 22,ooo 20,000 18,000 and sourcetemperatures were 205o and 275oC,re- spectively. UV-uisibleand massspectrometric results I The UV-visible spectraobtained on fragmentsof z abelsonitefrom two samples(Wosco and DoE/ Lnnc) werethat of a porphyrin(Falk, 1964)having spectralbands at 392, 5lO,and 550 nm in benzene (Fig.7) and 390,512,and 552nm in acetone.The data suggestthat abelsoniteis a deoxophylloeryth- roetioporphyrin-type(DPEP) porphyrin with an isocyclicring. The presenceof a smallpeak at 618nm in the acetonevisible spectrum of abelsonitefrom the Fig. 7. UV-visibleabsorption spectrum (in of typeabelsonite Wosco samplesuggested the presenceof about 14 benzenesolution; curves represent two differentdilutions). percent(of total pigment)free-base porphyrin. How- was observed;other recorded using a Beckmanl Acta CIII and a Perkin- ever, only the 618-nm band were by Elmer Model 350 scanningspectrophotometer. The bands of the free-baseporphyrin obscured at and 552nm. infrared spectral data were obtained on a 30 pg the metalloporphyrinbands 512 (1967)have shown that X-ray sample using infrared microsampling techniquesde- Donnayand Storm patterns end-membersof the iso- scribedby Estepet al. (1973).Micropellets were scan- powder of eventhe porphyrin (TTP) and ned on a Perkin-Elmer Model 2l prism spectropho- morphousseries tetraphenyl (AgTTP), the free-base tometer (2-15 m) and a Perkin-Elmer Model 621 silver tetraphenylporphyrin porphyrinand grating spectrophotometer (5000-200 cm-1), both and silveranalogs of the GreenRiver porphyrin, Thus, abel- equipped with reflectingtype 6X ultra-micro beam nickel are indistinguishable. a non-stoichiometric condensers.Mass spectrometricanalyses were made sonitemay best be thought of as using a Dupont 491-BR mass spectrophotometer compound. Massspectrometric analyses (Fig. 8) of an abelson- I Equipment named in this report is for identificationonly and ite samplerecorded at 70eVshowed that the major does not necessarilyimply endorsement. mass/charge(m/e) peak was 518 and a secondary

5$ 520 5r0 5m Fig. 8. Partial l2 ev massspectrum of abelsonitefrom GreenRiver Formation,Utah. 936 MILTON ET AL.: ABELSONITE

The molecularweight of 518 indicatesthat this nickel porphyrinhas 3l carbonsand not 32 as was suggestedearlier (Pabst et al., 1975).The empirical formula for abelsoniteshould then be Cg,HazNnNi; thecalculated composition for C'HrrNoNi (in weight percent)is: C 72.33,H 6.07,N 10.55,Ni 11.05.A proposedmolecular structure for abelsoniteis shown ,,"'\ -" in Figure9. It is not possible,at present,to presenta \:\/.:2 more specificmolecular structure. Infrared spectromet ry results The general characteristicsof the infrared spec- Fig. 9. Proposed molecular structure of abelsonite,C'HrrNoNi; trum appearin Figure 10,curve b (obtainedon the nickel 8-desmethyldeoxophylloerthyroetioporphyrin. Roman numerals I-IV are cyclic tetrapyrrole rings; V is a cycloalkane ring. prism instrument).Frequencies for C-H stretching vibrations,which were well resolvedinto threecom- m/e peakwas at 520.The ratio of the 518to 520mass ponents(2970, 2915,2860 cm-') in the gratingspec- spectralpeak intensities roughly corresponds to the trum, suggesta predominanceof aliphaticgroups in naturalabundance of the two major stableisotopes the structure.The absenceof a strong absorption of nickel(Niu' : 67.8percent and Ni6o: 26.2per- band in the C : O stretchingregion of 1780-1630 cent). cm-r indicatesthat thereare no carbonylgroups in

FREQUENCYar-I

t I ri iitr - $ z = z

WAVELENGTH,pn

FREQUENCY,6m-1 5,000 3,000 2,000 1,500 r,200 1,000 900 800 | , | , i,,',1,' , ' | , | | , I 1,,,,t,,1

I I U 6 z. 4Y \n/rl F vv F s 1r = it \-r n/ " z 2) 17 \I F 2 S=aSILICATE

10 ll IZ 13 T4 l3 WAVELENGTH,rm Fig. 10.Infrared absorption spectra of nickel-porphyrincomplexes. (a) Nickel-etioporphyrinI (synthetic API No. 1906,nujol and fluorolubmulls); (b) Abelsonite(Wosco, CsI micropellet). MILTON ET AL.: ABELSONITE 937 the structure. Additional absorption bands in the References low-frequency mid-infrared region of the spectrum AmericanPetroleum Institute (1957) Selected ualues of properties : were observedat 620(w weak) 602 (w) 535(w) 512 of hydrocarbonsand related compounds.Category B. Infrared (w) 441 (s : strong) and 392 (w) cm-l. Absorption spectraldala Loose-leafdata sheets, serial nos. 1906, 1907, 1908. bandsat 3430(m : medium) 1635(w), 995(w) cm-1 ResearchProject 44. (labeled"S" in Fig. 10,curve b) and at 440 cm-1 (s) Buerger,M. J. (1963)Elementary Crystallography. Wiley, New York. (observedin the grating spectrum)matched well with Cashion,W. B. (1967)Geology and fuel resourcesof the Green the major absorption bandsin the spectrumobtained River Formation,southeastern Uinta Basin,Utah and Colo- for the fine-grainedblack material that abundantly rado. U.S Geol.Suru. Prof. Pap.548. coated the surface of the host rock. A microscopic Crute,M. B. (1959)The crystalstructure of nickeletioporphyrin examination of the three translucentgrains of abel- lI. Acta Crystallogr.,12, 24-28. Donnay,J D. H., G. Donnay,E. G. Cox,O. Kennardand M' V. sonite used to obtain the infrared spectrum showed King (1963)Crystal Data: DeterminatiueTables,second edition. severaloccluded black specks.The spectrum of the AmericanCrystallographic Assoc. Monograph No. 5. black material isolated from the host rock indicates Donnay,G. andC. B. Storm(1967) Molecular solid solutions of that it is an hydroxyl-containinglayer silicate (pre- tetraphenylporphyrinand silvertetraphenylporphyrin. Molecu- sumably the "micaceousmineral" referredto above). lar Crystals,2, 287-292. Estep,P. A, J. J. Kovachand C. Karr, Jr. (1973)Microsampling Since the infrared spectrum of a nickel desmethyl techniquesfor infraredspectroscopic analysis of lunar and ter- DPEP was not availablefrom the literature for com- restriaf minerals.In Analytical MethodsDeueloped for Appli- parison with that of abelsonite,a comparison was cation to Lunar SamplesAnalyses, p. 80-99. ASTM STP 539, made with that of nickel-etioporphyrin I (Fig. 10, AmericanSociety for TestingMaterials, Philadelphia. Elsevier,Am- curve a, American Petroleum Institute, 1957).There Falk, J. E. (1964)Porphyrins and metalloporphyrins. sterdam. are gross overall similar spectralcharacteristics, but Fleischer,E. G. (1963)The structureof nickeletioporphyrin I. "/. minor differencesindicate a different structure, as Am. Chem.Soc.. 8J. 146-148. was verifiedby UV-visible and mass spectraldata. Moore,J. V. and H. N. Dunning(1955) Interfacial activities and porphyrincontents of oil shaleextracts. Ind. Engr.Chem,47, Acknowledgments 1440-1444. Weare grateful to LawrenceC. Trudell, Dor/LEnc, for bringing Pabst,A., P. A. Estep,E. J. Dwornik,R B. Finkelmanand C. thisunusual mineral to our attention.We wouldalso like to Milton (1975)Crystallized nickel porphyrinfrom the Green expressour appreciationfor assistanceto the followingcolleagues River Formation,Utah (abstr.).Geol. Soc. Am. Abstractswith at theU.S. Geological Survey: Mary E. Mrose,Michael Fleischer, Programs,7, 122l-1222. IrvingBreger, W B. Cashion,and James Lindsay; also to Daniel Sugihara,J. M. andL. R. McGee(1957) Porphyrins in gilsonite..I. Appleman,Smithsonian Institution, Washington, D.C.; to Profes- Org. Chem, 22,'195-798. sor CarlyleB. Storm,Howard University;to Dr. Akira Kato, Trudelf, L. (1970)Lithologic Desuiption of lVesternOil Shale National ScienceMuseum, Tokyo; to Dr. Virgil L. Goedken, Corporation Project lJtah EX-1. Larcmie Petroleum Research FloridaState University, Tallahassee; and to Dr. Earl W. Baker, Center. Florida Atlantic University,for aid in interpretingthe massspec- trometricdata and useof theDupont 491 BR massspectrometer and BeckmanActa C I I I spectrophotometerin his laboratory. Manuscript receioed, January 23, 1978; accepted This investigationwas supported by NSF grantT4-13319. for publication, May i,8, 1978.