HENDERSONITE, a NEW CALCIUM VANADYL VANADATE from COLORADO and NEW MEXICO1 M. L. Lrxrsenc, A. D. Woors, M. E. Tnourson,2 D. P. E

THE AMERICAN MINERALOGIST, VOL. 47, NOVEMBER-DECEMBER, 1962

HENDERSONITE, A NEW CALCIUM VANADYL VANADATE FROM COLORADO AND NEW MEXICO1

M. L. Lrxrsenc, A. D. Woors, M. E. TnoursoN,2 D. P. ErsroN, .qNoRonBnr Moynowrrz, U. S.Geologicol Suraey, Washington25, D. C.

ABSTRACT In 1955, hendersonite, a new vanadium mineral with the theoretical formula Ca2H"V4+(r+')V5+re (with r<0.1 in the analyzed samples) was found in the "lO:a'8H:O J. J. mine on the south side of Paradox Valley, Montrose County, Colorado, and in one of the Eastside mines (on the east side of the Carrizo Mountains), in San Juan County, New Mexico. Both mines are in vanadium-uranium deposits in the Salt Wash Sandstone Member of the Morrison Formation (Upper Jurassic). The mineral occurs in partly oxidized ore. Hendersonite is greenish black to black and forms aggregates of microscopic bladed to fibrous crystals in thin seams along bedding planes and in small arcuate veinlets bordering unoxidized ore. The mineral is biaxial, negative, with parallel extinction. Both 0 and "y indices are above 2.01 and the a index is lower than 2.0; the mean index calculated from the Gladstone-Dale formula is 2.10. The orientation is X:o perpendicular to the platiness or blades, Y: 6, and Z: c parallel to the elongation. The optic angle 2V is medium; disper- sion r)v is weak; pleochroism moderatel absorption X yellow-green, Y green, and Z brown. H is about 2.5; G measuredon J. J. mine samplesis 2.77+0.05, and on the Eastside mine sample, 2.79+ 0.01. Hendersonite is orthorhombic with probable space grotp Pnam (\o. 0Z; or Pna21 (No. 33). Unit cell data on the New Mexico sample are: a:12.40+O.O4 A, b:18.92*0.08, and. c:10.77*0.03; a:b:e::0.655:1:0.569; cell vohme 2527 A3; cell contents 4[Ca2H"V4+(r+")V5+ra-,lOzr'8H:Olcalculated density 2.806g/cm3. The strongest ]ines of the *-ray diffraction powder pattern are 9.45 A (intensity 100), 3.113 (36), 4.70 (16), 3.237 (12),2.788 (12),3.788 (9), and,2.2ffi (9). The powder pattern is the most satisfactory means of distinguishing hendersonite from the other dark-colored vanadium minerals. The new mineral is named for Edward P. Henderson of the U. S. National Museum in Washington, D. C.

INrnooucrroN AND AcrNowrBocMENTS In April 1955 the first sample of this new vanadium mineral was collected by D. P. Elston during his mapping and geologic study of the J. J. mine, Paradox Valley, Montrose County, Colorado, and later he found additional material in the samemine. In June 1955,A. D. Weeks collected a suite of ore samples from the Eastside mines, San Juan County, New X4[exico,and found more of the same new mineral. Min- eralogicand preliminary n-ray study of the J. J. mine samplewas made by M. E. Thompson. Elston studied the geologicsetting of this occur- rence (Elston and Botinelly, 1959). The mineralogy and geologic

I Publication authorized by the Director, U. S. Geological Survey. 2 Present address, Department of Geology, Harvard University, Cambridge, Mass. 1252 HENDERSONITE 1253 occurrenceof the Eastsidemine samplewere studied by Weeks,and an extensive and definitive rc-raystudy of this sample was made by M. L. Lindberg. We are indebted to our colleaguesH. T. Evans and C. L. Christ for suggestionsin the preparation of the manuscript. The preliminary investigation of the new mineral was part of a pro- gram of geologic and mineralogic studies carried out by the U. S. Geo- Iogical Survey on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission. The new mineral is named hendersonitefor Edward P. Hendersonof the U. S. National Museum, Washington, D. C. Among his numerous mineralogic studies he contributed to the knowledge of the vanadium- uranium ores of the Colorado Plateau and described several new vanadium minerals: f ervanite(Hess and Henderson,1931) , corvusite(Hender- son and Hess, 1933) and steigerite(Henderson, 1935).

OccunnBNcn Hendersonite, Ca2H,V4+(r+")V5+(e-")O2a.8H2O,has been found in two mines that are 120 miles from one another. Both of the mines are in vanadium-uraniumdeposits in the Salt Wash SandstoneMember of the Morrison Formation (Upper Jurassic)and are on the ColoradoPlateau. The J. J. mine (Fig. 1) has been describedby Elston and Botinelly (1959).It is adjacent to the Thunderbolt mine at the easternend of the Jo Dandy mining area, and is on the south side of Paradox Valley, Nlontrose County, Colorado. The geology of a part of the Jo Dandy areaand the location of the Thunderbolt mine are shown on the geologic map of the Naturita NW quadrangle,Colorado (Cater, 1955).Paradox Valley trends northwestward toward the La Sal Mountains in eastern Utah, and is incised along the axial part of an elongatesalt structure. Although strata overlying and flanking the salt structure are cut by faults at many places, only a few minor faults are present in and near the J. J. mine. Near the portal of the mine the sandstonebeds strike about N. 64' W. and dip 10o-14o SW. The mine workings, from the portal to about the middle of the mine, are nearly along the strike of the beds, but from the middle to the innermost part of the mine at the claim line the workings trend almost down the dip. In the rear one-third of the mine the workings intersect the local water table and the water saturation has protected the ore from oxidation. Below the water table, the ore is largely unoxidized and consists of vanadium silicates, montroseite, uraninite, and coffinite. Disseminated pyrite and marcasite are commonly associated with unoxidized ore; where oxidation has occurred the rock is freckled and streaked light to dark brown by iron oxides. 1254 LINDBERG, WEEKS, THOMPSON, ELSTON AND MEYROWITZ

il \*5ffi

DOLORES

MONTEZUMA

J coLoRADor i NEW MEXICO

S AN JUAN

Shiprock

C lO zomiles

Fro. 1. Index map of part of Colorado Plateau, showing location of J. J. mine, Montrose County, Colorado, and Eastside mines, San Juan County, New Mexico Above the water table, in the middle part of the mine, remnants of relatively unoxidized rich ore associatedwith abundant coalifiedplant material are surroundedby oxidizedlower-grade ore that is disseminated in sandstone(Fig.66, Elston and Botinelly, 1959). Hendersoniteis in partly oxidizedore that bordersunoxidized ore, and it is associatedwith HENDERSONITE 1255 paramontroseite (VOt, simplotite (CaVrOs'5H2O), melanovanadite (2CaO' 2VzO+'3VzOs' HzO ?), sherwoodite(Ca3VeOzr' 1sHrO) and corvusite (VrO+.6VzOs.nHzO?). Close to the portal of the mine the ore is mostly oxidized and consistschiefly of carnotite and vanadium silicates. Evans and Garrels (1958, p. 142-147) considered the fields of thermodynamic stability for the vanadium minerals, and the sequence of minerals formed by progressiveoxidation; the J. J. mine displays this oxidation sequencevery well. Hendersoniteforms in thin seamsand veinlets, filling fractures that are roughly parallel to the bedding of the sandstonewithin pods and thin layers of rich, partly oxidizedore. The seamsof hendersoniteare a few tenths of an inch or less in thickness,and are commonly less than 12 inches long. Exposed surfaces of the veinlet's are tarnished blue-black. The high luster of the hendersoniteveinlets is distinctive against the generally dull background of the surrounding sandstone. The formation of hendersonite is spatially related to sulfide-rich "eyes," many of which are enclosedin pods or thin layers of rich ore' The sandstonein the "eyes" is light gray, friable, and weakly cemented by abundant microscopiccrystals of pyrite and marcasite.It is poor in vanadium and uranium minerals. Small amounts of goethitb, meta- tyuyamunite, and unidentifi.ed, sooty black (carbonaceous?) material are present in the outer part of the sulfide eye. At one place a thin arcuate veinlet of hendersonite is faintly distinguishable on the periph- ery of the partly oxidized border of a sulfide eye. The veinlet is bounded on the outside by a thin zone oI pale-red, yellow and green minerals admixed with fine-grained black to blue-black minerals, which in turn gradesinto the enclosingrich black ore. At another place a thicker and distinct veinlet of hendersonitefills part of a fracture that is parallel to the bedding. The fracture transects, in succession,weakly mineralized.and barren rock, rich ore, and a sulfide eye that is enclosed in the rich ore. The fracture filling consistsof hendersonitewhere it is bordered.by rich ore but consists of gypsum where it is bordered by weakly mineralized rock and by sulfide-bearingrock' The field relations at the J. J. mine indicate that hendersoniteis formed,in places where rich ore that is in proximity to sulfide-rich rock is subjectedto fairly rapid but restricted oxidation. Hendersonitealso was found in one of the Eastsidemines in San Juan County, New Mexico (Figs. 1 and 2). The minesare on a small,irregular- shapedmesa (indicated as King Tut Mesa by Stokes,1953) the surface of *trich is a dip slope of sandstonegently inclined to the east, on the flank of the Carrizo Mountains (Strobell, 1956).Because the Salt Wash SandstoneMember (Morrison Formation) is exposedon the entire mesa' 1256 LINDBERG, WEDKS, TI:]O],IPSON, ELSTON AND ML.YROWITZ

EXPLANATION

IGNEOS FOCKS li'/ | lnkusivedio.ire dikes ond piugs

TJ-l:in li''s'ri Shol1e.edsedime.lory rccks inlrudedby rgftousmol.rols

SEDIMENTAFYrcCKS ;a l-6r Doloto b6ron€ j,'D (unconrorn ty)

"o\

Morrison Formorim Jmb Brushy hrn hber Jmw Wssl{ot.r &nyon Memb€r Jmr R.coptu.s Mcmb.. Jms Soli Wosh M€mb€r

I Jbr I Blufl Sondslon€od Summ.rvill.

f;_l

Entrodo $ndslone

th"_l

winqdl'sondslone xo4?, E Chln16Fornotion / Mine odif

G.ol09! hodified fiom Slrchll ,1956 lnclined Siofl

sorprLcotion

Frc. 2. Geologic map of vicinity of Eastside mines, San Juan County, New Mexico. the ore is at shallow depth and is mostly oxidized (Weeks,et al., 1959, p.77).The chief ore mineralsare vanadium silicates,carnotite, and tyuyamunite. Within the Eastside group of mines, hendersonitewas found in the mine which has the thickest cover. This mine is located about midway between the mesa rims at the "neck" of the mesal it was called the Nelson mine at one time (J.D.Strobell Jr., writt. comm., 1961).In June 1955,when the hendersonitewas collected,access to the workings was obtained through two nearly horizontal adits from the south side of the mesa.The workings connectedfrom the westernmostof the two HENDERSONITE 1257 adits to the baseof the only inclined-shafton the mesa.The new mineral was found in the working face of a drift that extended about 60 feet eastwardfrom the foot of the incline. The roof of the mine at the face consistedof hard, tightly cemented sandstone,underlain by two feet of thinly beddedmineralized sandstone. NIany beddingplanes in the ore zone contained films and seams, as much as one-fourth inch thick, of vanadium minerals, chiefly hewettite and hendersonite.Gypsum wds present along many bedding planesin the vanadium-rich zone, as well as in irregular fracture trllingsin 1] feet of mudstonebeneath the sandstone. Although most of the ore in the Eastsidegroup of mines is oxidized becauseof its shallow depth, partly oxidized ore minerals in addition to the hendersonite were found in several places. In a drift from the east adit of the Nelson mine, greenish-black corvusite occurs as a mineralized border between a sandstone bed and a pelletal clay bed. In the Shadysideno. 1 mine which is just northeast of the incline and which has a horizontal adit below the rim of the mesa, one long drift extendstoward the Nelson mine. The Shadysideno. 1 mine is the locality from which one of the fi.rst samplesof sherwoodite,another calcium vanadyl vanadate, was found in 1952 (Thompson et al., 1958)' A revisit to the Shadysidemine in 1955showed that the deepestpart of the mine, which was closeto but was not interconnectedwith the Nelson mine, contains several patches of partly oxidized blue-black corvusite ore. Bright orange coatings of pascoite formed by evaporation of moisture from the corvusite ore are present in small quantity. The mines on this mesa, in general, are moderately dry and very little modification of the ore is still in progress. In contrast to the J. J. mine, the Eastside mines now contain little or no unoxidized ore and only a few patches of partly oxidized ore in protected places. Iron oxide stains and streaks indicate the former presenceof disseminatedpyrite and are typical of oxidized ore sandstone on the ColoradoPlateau. There is no reasonto suspectthat the oxidized and partly oxidized ore at the Eastside mines was not derived from un- oxidizedore, as at the J. J. mine. Pnvsrc'q.r-eNo Oprrcar- PnopenrrBs The crystal system of hendersonite is orthorhombic, as suggestedby optical properties and indicated by r-ray study. Fresh surfaces of the mineral are dark greenish black to black, with luster ranging from pearly to subadamantine. Exposed surfaces gradually turn brownish. The mineral occurs chiefly as aggregatesof subparallel to parallel microscopic fibers or blades. Some of the material from the J. J. mine is in 1258 LINDBERG, WEEKS, THOMPSON,ELSTON AND MEYROWITZ

elongated,six-sided platy crystaisand displaysa perfectcleavage parallel to the platiness.One of these relatively rare platy crystals is shown in an electron micrograph taken by Ross (1959, Fig. 3) and the more common bladed to fibrous habit of the minerai from the Eastsidemine is shown in Ross'sFig.5 (1959).The fiber aggregatesfrom the Eastside mine break into smaller bundles when pressedgently with a needlebut the fibers begin to smear when pressedfurther. They are only slightly less smearing than typical corvusite, and much less brittle than the nonsmearingmicroscopic needles of nontroseite.In general,the corvusite-type minerals and carnotite and tyuyamunite all smear very easily becauseof their layer structures. The streak of hendersoniteis dark brownish green. Hendersoniteis about 2.5 on the Mohs scaleof hardness.Under the binocular microscope,a fiber bundle can be seen to scratch gypsum easily, but it rubs off on calcite. Coherent aggregatesof hendersonite from the J. J. mine, weighed on a Berman balance, yield a specific gravity of 2.77. A difierent method of determining the specificgravity of the sample from Eastside mines diluting bromoform untii loose

[ [F c. 3. Powder ancl fiber n-ray patterns of hendersonite from the Eastside Carrizo mine: (A) fiber pattern, Ni-filtered Cu radiation; (B) powder pattern, Ni-filtered Cu radiation; (C) powder pattern, V-filtered Cr radiation; (D) fiber pattern, V-filtered Cr radiation HENDERSONTTE 1259 fibers of hendersonitewere suspendedin the liquid and weighing the Iiquid, gave 2.79. The measured values agree satisfactorily with the calculateddensity of 2.80s,g/c:rrl}. Hendersoniteis biaxial negative with extinction parallel to the fiber length and the long dimension of the platy grains. The indices cannot be accurately determined; two indices 0 and y are above 2.01 (the highest available index liquid), and the a index, although lower than 2.01,is uncertain becausethe microscopicallythin bladeswill not stand on edge. The mean index of refraction calculated by the Gladstone- Dale formula is 2.10. This is the same as the mean index of hewettite, which has indicesa : 1.77, A: 2.I8, and 7 : 2.35"(Hillebr and et al., l9l4) . The X axis is perpendicularto the platiness'or broad surface of the blades, Y is acrossthe blades, and Z is parallel to the elongation of blades and fibers; X:4, Y:0, and Z:c. The crystals are moderately pleochroic,the absorption is X yellow green, Y green, and Z yellow brown to brown.

X-nev CnvsrerrocRAPHY Hendersonite consistsof bundies of fibers oriented parailel to the fiber axis, c. N,Iostburidles of fibers show random orientation around c. The sample from the Eastside mine in New Nlexico was used for the detailed r-ray study. A multiple fiber yielding one strongerand several weaker diffraction nets has been studied by rotation, Weissenberg,and precessioncamera techniques,without remounting the fiber; the single 'Iables crystal data derived from the strongestof the nets are listed in I,2 a"nd3. The pattern obtained by rotation parallel to the c-axisshows very stronglayer linesfor l:0 and for l:3n and very weak intermediate iayer lines; the hk} and hh3 lattice levels are the only Weissenberg patterns attempted. The precessionpatterns h\l, hll,Ukl and lkl are weaker patterns than are usuaily used to observespace group criteria. Hendersonitehas orthorhombic symmetry. Possiblespace groups con- sistent with the observedsingle crystal reflections are Pnam (No. 62) or Pno21(No. 33). AII possibled-spacings, including thosefor reflections not permitted by the spacegroup Pnom, (or Pnc2r) have beencalculated to determine whether the reflectionsobserved on the powder or fiber patterns, Table2 and Fig.3, can be properly indexedon the basisof the spacegroups chosen.It was found that this wl.s indeed the case. The directionsfor the crystal axesin henderscnitehave been chosen following the convention clalb for the orthorhombic system. Ross (1959) in electron diffraction studies of hendersonite(then unnamed) interchangedthe 6- and d-axes;the direction labelledb* in the SAD spot pattern,his Fig. 4,p.329, becomesct'in the presentstudy. His electron 1260 LINDBERG, WEEKS, THOMPSON, ELSTON AND MEYROWITZ

Tnsrn 1. Cnlsrar- Dare ron Hertnnsonrrr

Present study Eastside Canirc mine Eastside Carrirc Mine J. J. mine

a rz.+o+ool A a rz.rs+o.orA 12.181001 A b 18.92t 0.08 b c 10.77 t 0.03 3c 10.836t0 012 r0 88110.009 io 3.5910 01 c 3 612+0 004 3.627I 0.003 a:b:c 0.655:1:0.569 Vol. unit cell zszzL" Gram-molecular weight (obs.) 4246 Specific gravity (obs.) 2.79!0 .O12 Specific gravity (calc.) 2 800 Formula proposed CazHsVa+111a1V5+1r-z)Oa.8HrO z Space Group - Pnam (No.62) or Pna2r (No. 33

t Ross (1959) interchanged D and c,'he noted the very weak spots which appeared to triple his D-uis, but recorded the axial length for the smaller cell; the transformation matrix from his cell to the present one is 100/ool/60i data from electron difiraction studies of samplesprepared by suspensionin water. z Determined by dilution of bromofom until mineral grains were suspendedand measuring specific gravity of liquid.

diffraction pattern, if indexed as aL h\l pattern, shows no systematic extinctions; on the tr-ray diffraction patterns patterns only those hol reflections for which h:2n and only those 0fr1 reflections for which kll:2n are observed.The intensity distribution includesdifferences not related to stronger electron difiraction and weaker tr-ray diffraction patterns. The conditions obtained for hendersonite are probably similar to those describedby Ross and Christ (1958) for colemanite;in both hendersonite and colemanite, the crystal is extremely thin in the b* direction, and electron-diffraction spot patterns are to be indexed with the * parameteras a variable (Table 3). Ross and Christ show that if a crystal is thin in the b* direction the reciprocallattice points become rods elongated parallel to that direction. upper level rods extend into the sphere of reflection and are coincident in projection with zero level rodsl hence the appearance of "forbidden', Z0l reflections. Rotation patterns of hendersoniteshow that the repeat period of the fiber-axis is 3.59 A i.r the small pseudo-cell and tO.iZ Ft in the large true cell. By analogy with other vanadium-oxygen coordinated minerars, the smaller repeat period is related to the stacking of units of VrOs; the repeatperiod 3.59 A is of the sameorder of magnitudeas that found for chains of vanadium linked in five-fold, (Christ, et at., l9S4) or in mixed five-fold and six-fold coordination with oxygen (Evans, 1959, p. 99); or as the length of sheetsof VeOeformed by VOooctahedra and VOo distorted trigonal bipyramids sharing edgesand corners (wadsley, 1957). The larger repeat period probably results from the way in which VaOe units link with calcium and with water of crvstallization. HENDERSONITE t261

Tesln 2. X-Rev Powonn Dare lon HnNnrnsoxrtr

HendeBonite from Hendersonite from New Merico Coloradoa

Calculatedl Measured lated Measured

Fibera Powders Powder al

Cu/Ni Cr/Y Cu/Ni Cu/Ni dntt . I \:1 5418 )\:2 2902 I :1.5418A )r:1.5418 A

dnt"o dlrl dnnt dnt"t dntot

010 18.92 C 18 80 100 12.40 C 12 22 001 1o.77 C 10.95 110 10 38 C 10 40 10.36 r0 37 9 10.36 10.25 w r0 25 020 9 46 S 946 944 100 9 45 100 9.43 9.40 VS 940 011 9 36 P P 9.46 101 8 13 815 120 7.52 w 750 750 6 7.50 8 7 51 747 747 111 7 47 P P 7.48 o21 7 -11 7.15 030 6.31 6.27 200 6 20 M 621 621 8 6.20 11 620 6.11 6.17 t2t 6 r7 P P 616 2to 5.89 1\ 6.88 < 1 5.88 5.81 130 5.62 561 <1 5.59 5.59 031 5 44 P P 5.46 002 5.39 w 5.38 1 5.37 5.47 w 537 201 5 37 P P 533 otz 5 18 526 220 5. 18 w 5 17 5 17 11 5.18 5.12 w 5.18 211 5.17 P P 5. lJ 102 4.94 1 4.98 4.99 131 4 89 P P 498 497 112 4.78 4.83 040 4 73 4.72 472 4.70 17 470 4.70 M 4.69 o22 4.68 4.73 221 4.67 4.64 140 4.42 N 4.40 230 4 42 w 442 442 439 3 4.42 4.38 440 I22 4 38 441

rdl,6lcalculatedfromthefollowingdata:a-124O!OO4,b:18.921008,c:10 77l0.03A.Allcalculated d-spacingslisted for d ) 2 07 A. , Single crystal intensities estimated visually from the hk, and hk3 Weissenbergfilns from a multiple fibet yielding one strong and several weaker nets; exposure tine approximately one week; S:strong, MS:medium strong, M :medium, W :weak, VW:very weak, C :cut-ofi, upper limit of measurable d approximately 10 A, N:not distinguishable from background (absent or identification of reflection doubtful due to superposition of a reflection belonging to another net). 3 114 59 mm diameter camera Film measurementscorrected lor shrinkage. Lower limit of 20 measurable: approximately 7'; Q:reflection corresponding to qtartz, known to be present as impurity in the sample, intensity of reflection uneven and difficult to measure. The approximate d-spacing oI the hk| reflections visible in the fiber pattern is denoted by P; the actual d-spacingshave not beenmeasured because the arcs made by the reflections do not intersect the0-level. aDataof MaryE Thompson.d14Tcalculatedfroma:12.22,6:18.80,c:10.95A.11459mndiameter camera VS :very strong, MW:medium weak, F :{aint, VF :very faint, b:broad, other symbols in {oot- note 2. 1262 LINDBERG, Wtr:,EKS, THOMPSON, ELSTON AND MEYROWITZ

TlteLn 2. (continued)

Hendersonite from Hendersonite from New Mexico Coloradoa

Calculatedl Measured Calculated Measured

Fiberr Powderr Porvder

CulNi Cr/Y Cu/Ni Cr/Y hht du"t . CulNi X - 1.5418 I :1 5418A \:2 2g0g2A r:1 5418,[ A

dr,,to dr,il dn*t dnt"t r dn*t

041 4.33 4.33 300 4.113 o 426 4.07 W,b 404 o32 4 095 4.1.3 141 4.090 P P 408 231 4.090 P P 202 4.065 4 074 407 310 4.037 4.031 4.040 4. 053 4 040 398 212 3.975 398 132 3 888 3 91. 301 3.860 3 81 320 3 788 M 3 789 3 786 3 788 3.789 3.74 MW 378 050 3 784 N] 311 3 781 374 240 3.761 3. 758 3 759 3.73 222 3 736 3.74 150 3 619 W 3 606 3.604 3 606 w 3.59 003 3 590 365 321 P 3.54 051 3 570 P o42 J, JJ5 357 241 3.550 3.53 013 C 358 330 3 457 M 3 460 3 451 3 456 342 w 345 103 3 449 c 349 151 3 .43r 232 3 416 342 142 3 416 343 113 3. 393 S 3 387 3 3 388 343 023 3.357 c 3.343 o 3.340 340 F 339 331 3.292 3.26 302 3 279 326 123 3.240 S t2 3 237 6b ls zso 328 312 3.231 \3 221 322 w 3.22 250 3.230 M 3 224 3-22i 060 J I5.' w 033 3 120 M 340 3.113 S 3 110 3.110 36 3 108 308 MS 3.10 203 3.108 M 400 3. 100 M 3 .055 322 3.098 309 o52 3.096 251 3 .093 242 3 084 213 3 066 410 3 0s8 N 160 J.UJ5 \l HENDERSONITE 1263

T rsrn 2.- (conli.nued.)

Ilendersonite from Hendersonite from New Mexico Colorador

Calculatedr Measured lcu]ated Measured

Fibera Powdera Powder

Cu/Ni Cr/Y Cu/Ni Cr/Y CulNi dn*t. " \ :1.5418 I :1.5418A t :2 2g\g2 A I:1.5418 A

dr,r0 dn*o dn*t

061 3 026 133 3 026 3 026 3 021 3 05 F 3.O2 152 3 004 341 2 990 PP 2 965 401 2 979 PP 294 VF 223 2 952 w 297 420 2.945 N 2.940 2 940 290 4t1 2 943 2.90 161 2.940 332 2.909 2.90 043 2 860 2.89 42t 2 84r 2.8r 260 2 811 M 2 802 2.804 [ 2.8o3 350 2.790 M 2 799 2 790 I 2.286 MW 278 14s 2.786 S 281 233 2.786 W 2.80 430 2 781 2 475 252 2.769 062 2.721 261 2.720 303 2.7rr N 2.?r 070 2 703 1\ 351 2.702 342 2.695 2.68 004 2.693 274 431 2.693 2.665 402 2 687 2 689 2.67 2.68 313 2 683 2.69 014 2 666 2.7r 412 2.660 2 637 162 2 657 104 2.632 2.67 170 2.64r o7l 2 621 323 2.606 2.61 114 2.606 26+ 053 2 605 N 243 2 597 w 2. 586 261 F 259 440 2 s92 N 2.56 o24 2.590 2.63 422 2.583 2.565 17t 2.565 153 2.549 VW 2 .540 124 2.535 2.57 441 2.521 2.49 333 2.490 2 505 2 .500 2.49 W,b 2 50 1264 LINDBERG, WEEKS, THOMPSON, ELSTON AND MEVROWITZ

Trr.Lr. 2.-konti.nueil)

Hendersonite Hendersonite from New Mexico Colorador

Calculate Measured Measured

Powdert Powder

Cu/Ni Cr/\l CulNi Ct/Y Cu/Ni " X:1 5418 tr:2 l I:1 5418A" \:2 29092]Y X:1 5418A

dr,r0 dlr.0 dnt"t I dlti

500 2 480 1\ 270 2.478 M 2 471 2 472 352 2.478 034 2.476 2.51 432 2.471 2 455 204 2.470 2.468 2.472 2 495 W 2.46 510 2.459 214 2.449 2+7 134 2 428 2.46 361 2.417 246 o72 2.415 271 2 414 253 2 401 511 2 398 520 2.398 M 2.40 450 2.398 w 224 2 390 172 2 371 063 2 370 N 080 2 365 360 2 364 M lr ru 2.3ss 2 354 2.349 w 234 343 2 352 VW 2.35 403 2.346 MS I 234 MW 2.3r 52r 2 341 P P 451 2 340 P P o44 2 340 M2 2 336 413 2 328 N 163 2 i27 180 2 323 M t1 2.309 081 2.310 144 2 300 2.32 234 2.300 2.32 423 2 277 2 279 227 181 2 27r 370 2.26r MS 2.260 2 260 2 260 t6 2.257 MW 2.2s 531 2.256 P P 304 2.256 2.27 272 2.251 314 2 241 512 2 237 263 2,213 w 371 2 213 460 2.210 N 355 2 203 433 2 t98 2.t9 HENDERSONITE 1265

T*rn 2.-(continued.)

Ilendersonite from Ilendersonite from New Mexico Coloradoa

Calculatedt Measured Calculated Measured

Powder

CulNi cr/\ Cu/Ni Cr/Y CulNi hht dntt :1.5418 x :1.5a18a \=2.290s2 \=1.54184 A A

dt.*o dn*o dn*t dn*t

540 2.196 2.20 324 2.194 2.21 054 2.193 522 2.191 452 2.190 244 2. 189 2.205 46t 2.165 PP oE2 2.165 28t 2.165 PP r54 2.t60 o13 2.195 N 005 2 154 N 541 2.152 015 2.140 r82 2.133 173 2 127 334 2 124 2.135 105 2.t22 532 2.12r 115 2 rO9 443 2.tO2 \T 2.10 090 2.102 o25 2.100 372 2 086 190 2 073 w 125 2.071 550 2.O70 MS 2.O75 2.076 2 069 2.069 254 2 068 600 2.067 w 2 050 2 051 4 2.049 6 2.046 MW,b 2.040 2.036 2 2 034 2.033

2.O21 J 2.O21 3 1.996 1.989 3 1.951 4 1.947 8 1.797 1.796 + 1.765 2 1.742 I 1.658

l-J5/ 2 1.532 2 1 506 3 |.473 1266 LINDBERG, WEEKS, THOM?SON, ELSl',ON AND MEYROWITZ

Telrr 3. CoupenrsoN or,Onsnnvnn INrnNsrtros: ElrcrnoN ann X-Rev Drll.nacrroN Srunrns

X-Ray Diffraction2 Electron Difiractionl k:0 k:1 k:3

1k0 C C w 2k0 MW M w w 3k0 M w M M 4k0 M M 5k0 M M MS 6k0 M w 7k0 MW 8k0 VS MS MS w

0k1 c 1k1 C 2kl VW VW 3k1 VW 4k1 w Jt

0k2 w w tk2 VW 2k2 VW VW 3k2 W 4k2 w 5k2 VW 6k2 w 7k2 VW 8k2 w

0k3 MW M 1k3 S S S M 2k3 M M w VW 3k3 M w 4k3 S MS JKJ M w

I Electron diffraction intensities estimated visually by Lindberg from electron-diffraction pattern taken by Ross; indexing based on orientation of the unit cell used by Lind- berg, in the present study; for transformation matrix see Footnote 1, Table 1. 2 Single crystal intensities i:stimated visually from various Weissenberg and precession films taken with different exposure times; for intensities of reflections with & > 3, seeTable 2; for symbols used to deseribeintensities, seeFootnote 2, TabIe 2. HENDERSONITE 1267

Tnnr-n 3.-(continued)

X-Ray Difiractionz Electron Difiractionl k:0 l,-i l. -1 k:3

6k3 M w /KJ M 8k3 M VW

0k4 w W w 1k4 VW 2k4 VW 3k4 VW 4k4 VW 5k4 VW 6k4 VW 7k4 VW 8k4 VW

0k5 VW 1k5 VW 2k5 VW 3k5 VW 4k5 VW VW ok.) VW /KJ VW 8k5 VW

0k6 VS VS 5 1k6 MW 2k6 M VW 3k6 M 4k6 M VW 5k6 M 6k6 lva / lro MW 8k6 S w

CuBurc-q.rANer-vsps Several hundred milligrams of hendersonite were handpicked out of relatively pure samples from the J. J. mine and the Eastside mine. Each sample was crushed and further checkedfor impurity, the principal contaminant being quartz sa:nd grains enclosed in the hendersonite seam. The spectrographic analyses (Table 4) showed less than 0.5 per 1268 LINDBERG, WEEKS, THOMPSON, ELSTON AND MEYROWITZ

Tawn 4. Snurqu,tNrrrl.rrvB Sprcrnocnepmc ANelvsrs or Hnlornsoxrrn (Analyst:K. V' Hazel)

GJM-70 AW-14-55 J. J. Mine EastsideMine

Over10 per cent V V 5-10

l-J Ca Ca 0.5-1.0 0.1-0.5 Si, Sr Si,AI, FE 0 .05-0. 1 Mg Sr,Mg 0.01-0.0s AI, Ti, I'E Na, Ni 0.005-0.01 B 0.001-0.005 Mo Ba, Mn, Sc,Ti 0.0005-0001 Ba, Cr Cr 0.0001-0.0005 Cu cent Si, indicating probably less than one per cent impurity. The first two samples were then artalyzed.Later, another sample (GJM-70-1' RM-30) from the J. J. mine was analyzedin more detailed to seeif a separatedetermination of SrO and CaO would afiect the molecularratios and gram-molecularweight. The selection of the methods used by R. Meyrowitz lot the micro- chemicalanaiyses of sample GJI'I-70-1,RM-30 (Table 5) was guided by a qualitative spectrographic analysis of the mineral by Katherine V' Hazel, U. S. GeologicalSurvey, which showed aluminum in the range 0.1-0.5 percentand magnesillmin the range0'05-0'1 per celt; theseele- ments were not determined chemically. Four portions of the mineral were used for the analysis.One portion was used for the total HrO determination; a secondportion for the "insoluble," CaO, and SrO determinations; a third portion for the VzO+,total vanadium' and FezOr determinations;and a fourth portion for the HrO (-) determination' The weight of the variousportions ranged from 13 to 37 mg. The HzO was determinedby use of a modified microcombustiontrain of the type usedfor the determinationof carbonand hydrogenin organic compounds.The sample was decomposedby ignition at 900o C. in a stream of oxygen. The "insoluble" was determined by boiling the sample with (1t3) HNOB in a weighedEmich microbeakerand sinteredglass filter stick. The residuewas filtered, washedwith water, and dried to constant weight at 110+5" C. The filtrate from the "insoluble" determinationwas used for the CaO and SrO determinations.CaO was determinedby flame photometry (wave length:554s.). The samplesolution was comparedto stand' HENDERSONITE 1269

Teslr 5. ANer,vsnsor HnNoensolrrtn

Metal Oxygen Atoms per Ratios Equivalent Equivalent unit cellr

Analysis sample No. AW-14-552

CaOfSrO 8.84 o lt 166 .166 Ca*Sr 7.05 VzOa 8.01 8.45 .051 .toz v4+ 4.33 VrOr 63 44 66.97 368 .736 V6+ 31 25 Total HzO 14 45 15 25 .846 1.692 H 7r.84 Insoluble 428 Total Total 99.O2 oxygeq t29.8 equivalent HrO( )

Analysis sample GIM-703

CaOfSrO 993 10 45 . 186 Ca*Sr 7.90 VrOr 7.98 8.40 .102 v{+ 4 33 VzOo 63 21 66 54 .732 v5+ 31.08 Total HzO 13.88 14 61 | 622 H 6890 Insoluble 467 Total I Total 99.67 "Yc:".i 128.7 equrvalent J HzO(-) 7.53

Analysissample GIM-70-l(RM-30)4

CaO 95 9.7 .173 .173 t73 Ca 734 SrO 13 .o12 .o12 .o12 Sr 051 VrOr 81 83 050 . 100 .200 v4+ 4.25 VzOo 646 658 .362 I .810 v5+ 30.74 Total HzO t4.6 149 827 1 654 .827 H 70.22 FerOr <0.1 Total Insoluble 06 oxygen equivalent Total 987 HzO( )

1 In the three analyses, the atoms per unit cell are derived from the analyses recalculated to 100 per cent without insoluble by multiplying the metal and oxygen equivalents by 0.01 to convert flom a percentage to a Iractional scale, andby 4246, the gram-molecular weight of the unit cell contents, as deriwed from the unit cell volume and density of hendersonite lrom New Mexico; the gram-molecular weight from hendersonite from Colorado is assumed to be of the same order of magnitude. z Hendersonite from the Eastside Carrirc mine, San fuan County, New Mexico; Alexander Sheruood, analyst; ratios of mixed CaO and SrO calculated as all CaO. a Hendersonite from the J, J. mine, Montrose County, Colorado; Alexander Sheryood, analyst; ratios of mixed CaO and SrO calculated as all CaO. I Hendersonite from the J J. mine, Montrose County, Colorado; Robert Meyrowitz, analyst I27O LINDBERG, WEEKS, TEOMPSON, ELSTON AND MEYROWITZ

T,mrn 5.-(continued)

Analysis recalculated Metal Oxygen Atoms per Analysis to lOOTo Ratios Equivalent Equivalent unit cell without insoluble

Carvs+V4+8Or4. 8H2Ob

CaO 10 51 .1874 .1874 1874 Ca 80 VrOr 778 0468 .0936 1872 v4+ 40 VrOr 68.20 .3749 7498 1 8745 \rs+ 320 HzO 13.51 .7498 | .4996 .7498 H 640 Total Total 100.00 oxygen 2 9989 1280 equivalent

CarHo.rVl+rsrVa+r gozr. 8Hr0

CaO 10 51 1871 1874 1874 Ca 8.0 VrOr 856 .0515 10.31 2060 4.4 VzOr 67 34 .3702 7404 1 8510 v5+ 31 6 IIzO 13 59 7543 1 5086 .7543 H 64.4 Total ) Total 100 00 2 9987 o 128.0 "-"yc:l I equlvalent l

s Theoretical composition and ratios CarVa+V5+aOu.8HzO;the 2 of the gram atomic weights of four formula units is 4267. 6 Theoretical composition and ratios Carllo.rVa+r.rV6+ze0l.8HrO; the > of the gram atomic weights of four formula units is 4267- ard calcium solutionscontaining approximately the same concentration of vanadium presentin the solution of the sample.The Sr-O was determined by flame photometry (wave length : 461 mp). The sample solution was comparedto standard strontium solutionscontaining approximately the sameconcentrations of vanadium and calciumpresent in the solution of the sample. The VzOawas determinedby dissolvingthe mineral in (i*3) HzSO+ and titrating with approximately 0.03 N standard KMnO+. VzOs was calculatedby differenceafter the total vanadium was determinedspectro- photometrically using the hydrogen peroxide procedure.FerOe was determined spectrophotometricallyby the o-phenanthrolineprocedure. Ali- quots of the solution used for the VzOadetermination were used for the total vanadium and FerOsdeterminations. The HrO (-) was determined by drying the sampleto constantweight at 110+ 5oC.

DrnrverroN oF A FoRMULAloR HBNoBnsoNnB Chemical analysesof hendersonitefrom the J. J. mine, Montrose County, Colorado, and from the Eastside Canizo mine, New Mexico, HENDERSONITE l27l are given in Table 5. The numbers of atoms per unit cell, also listed in Table 5, have been calculated from the chemical analysesand from the unit cell data given in Table 1, without interpretation of possible com- bination of the atoms into a structural formula. The nearestnumbers of atoms, divisibleby four, which must be accommodatedin the unit cell if all equivalent positions are fully occupied, are 36 vanadium of mixed valence, 128 (or possibly 132) oxygen, and 8 calcium plus strontium. These,plus hydrogen,may be combinedas follows: 1) 4[Caz(%Oeh.SHzo] for 128 oxygen atoms 2) a[Caz(%Os)s'9HzO] for 132 oxygen atoms The chemicalanalyses show slightly more than four vanadium (IV) and slightly lessthan thirty-two vanadium (V). If the differencein electrical chargeson the vanadium atoms is balanced by an adjusted hydrogen content formula I and 2 may be expandedso as to indicate the valenceof the vanadium atoms: 3) 4[CazH"V6+(r+")Vz5(a-,)Ozr'8HrO]for 128 oxygen atoms 4) 4[CarH,V5+1r1,;V+51r"1Oza'9HzO]for 132 oxygen atoms where r approximates 0.1 in the three analyzedsamples. The total oxygen content of the three analysesis in closeragreement with formula 3; the hydrogen content is in closeragreement with formula 4; formula 3 is pre- ferred to formula 4 on the basis that the oxygen content is less variable than the hydrogencontent. The variable water content may be explained either as essentialwater, varying concomitantlywith a decreasedcalcium content,or asnon-essential, adsorbed water. The mixed vanadium (IV) vanadium (V) content representedby the a+ formula 4lCazH,Y

Cunrsr, C. L., Joew R. Cr-am e,NoH. T. Eva.Ns Jn. (1954) The crystal structure of potas- sium metavanadate monohydrate, KVO3.8HzO. Acta Crysl.71 801-807. Elsrou, D. P. .q.lro TtrBooonn Borrmnr.r.y (1959) Geology and mineralogy of the J. J. mine, Montrose County, Colorado; i.n U. S. Geol. Suney Prof. Paper 320, Pt. 18, 203-211. Eva.ws, H. T., Jr. (1959) The crystal chemistry and mineralogy of vanadium; in tl. S. Geol,.Suney ProJ. Paper 320, Pt. 7,91,102. R. M. Ganntr.s (1958) Thermodynamic equilibria of vanadium in aqueous systems as applied to the interpretation of the Colorado Plateau ore deposits. Geochitn. Cosmochim.Acta. 15, l3l-149. IlrxornsoN, E. P. (1935) Steigerite, a new vanadium mineral. Am. MineroJ.20,769-772. --- AND F. L. Huss (1933) Corvusite and rilandite, new minerals from the Utah-Colo- rado carnotite rcgion. Am. Mineral. 18, 195-205. Hnss, F. L. ero E. P. Hrxlonson (1931) Fervanite, a hydrous feric vanadate. Am. Mineral. 16, 273-277. Hrr.lennem, W. F., H. E. Mrnwrx AND F. E. Wnronr (1914) Heu,'ettite, metahewettite, and pascoite, hydrous calcium vanadates. Am. Phil,os. Soc.Proc.53, 31-54. Ross, Marcor.u (1959) Mineralogical applications of electron difiraction. II. Studies of some vanadium minerals of the Colorado Plateau. Am. Mineral. M,322-341. C. L. Cunrsr (1958) Mineralogical applications of electron diffraction. f. Theory and techniques. Am. M,ineral,.43,ll57-1178. Srnorur, J. D., Jn. (1956) Geology of the Carrizo Mountains area in northeastern Arizona and northwestern New Mexico. U. S. Geo|,.Surtey Oil Gas Inoest., Map OM 16O. Stoxrs, W. L. (1953) Primary sedimentary trend indicators as applied to ore finding in the Carrizo Mountains, Arizona and New Mexico. U. S. Atomic Energy Comm. RME-3043, pt. 1. TnowsoN, M. E., C. H. Roncn AND RoBERT Mnvnowrrz (1958) Sherwoodite, a mixed vanadium (IV)-vanadium (V) mineral from the Colorado Plateau. Am. Mineral,. 43,749-7 55. Weoslrv, A. D. (1957) Crystal chemistry of non-stoichiometric pentavalent vanadium oxides: crystal structure of Lir+"VaOe.Acta Cryst. l0r 26l-266. Wnnrs, A. D., R. G. Cor,ruerq AND M. E. TrolpsoN (1959) Summary of the ore mineralogy, i,n U. S. Geol. Suney ProJ. Paper 32O, Part 5, 65-79.

Manuseript recehted,May 12, 1962.