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