BRANNERITE, A NEW URANIUM MINERAL .*

BY

FRANK L. HESS, A.B., and ROGER C. WELLS, Ph.D.United States Geological Servev .

IN 1915 S . M. Ballard sent to one of the writers a highlyradioactive mineral that had been obtained from gold placersworked by Henry Sturkey in Stanley Basin in the central partof Idaho. Later other material was sent to the Survey by Mr .Sturkey . Mr. Sturkey's placer is near the head of KelleyGulch, said to be in granite cut by pegmatites, and it is in thepegmatites that the source of the mineral is probably to be found .

In t916 Robert N . Bell published a half-tone of a radiograph'made with the mineral by A. G. Van Eman, who thought it tobe euxenite, with which it is related in composition and which itresembles in color and texture .

The mineral received is in grains, part of which are prismsand most of which show a prismatic tendency (see Fig . i ) . Theyare a brownish yellow on the outside but the visible weatheringhas extended to a depth not exceeding the thickness of paper .Inside they are brilliant black, with a choncoidal fracture and nosign of cleavage . Polished specimens examined under reflectedlight show the mineral to be remarkably homogeneous . It is,however, traversed by minute cracks that are in part filled byquartz that undoubtedly accounts for the SiO., in the analysis .Although to the eye the mineral is an opaque black, under themicroscope very thin chips allow sufficient yellowish greenlight to pass to make possible optical measurements . The streakis a dark greenish brown . The hardness is about 4.5 as themineral will scratch apatite but will not scratch orthoclase .

The crystals are not perfect enough to allow a determinationof the crystal form, but their shapes suggest that they may beorthorhombic or. tetragonal . However, E. S . Larsen determinedit to be isotropic with an index of is , ~ - 2.26 +0.02 and a = 2±0.02 . It seems probable that it is an isometric paramorph aftereither a tetragonal or an orthorhombic form as many of the

* Published by permission of the Director of the IInited States Geo-logical Survey.

' Sixteenth Ann . Rept . Mine Inspector of Idaho (1915), Boise, pp . 29, 30 .

226

FRANK L. HESS AND ROGER C. WELLS.

1J. F. t-

complex pegmatitic uranium minerals seem to be . It will benoted in the tables given on other pages of this article that allbut one of the minerals (hielmite) arc isotropic . Yttrocrasiteshows hirefringent particles and is probably a mixture, Also like

Flu . 1 .

Branncrite pebbles and a piece of pitchblende ounted n

card to test comparative radio-activity . Slightly reduced . See figure un oPposito 15age,

nearly all of the complex pegmatitic minerals, the new mineralis variable in composition and the specific gravity of the speci-mens tested ranged from 4 .5 to 5.43, as determined with the Jolybalance . The specimens analyzed had a specific gravity of 5 .42

(by pyknometer) .

l'eb,IV20 .7 BRARNFRL7F, v'\EP T RAN[(JM MrNFRAL_

22 7

The radioactivity of the specimens of different specific gravi-ties showed slight differences as tested by the exposure of a

Ftc . 2 .

Radiograph made by the minerals shown in figure t . They were mounted on thin card-board which was laid on the sensitive film of a photographic plate for 48 hours . A print wasphotographed through a prism in order to make comparison easier .

photographic plate . Those having the highest specific gravityappeared most active (see Fig . 2) . The material was not testedin an electroscope. Attention may he called to the advantagesof making a radiograph of various specimens in a case of this

22 8

FRANK. L. HESS AND ROGER C. AVELLS .

[J . F . I .

sort before proceeding with the analysis, as it may be seen fromFig . 2 that some of the pieces were comparatively inactive, andpieces with a like content of uranium or thorium, or both maybe readily selected . Two of the least active pieces from theseventh row (Fig . 2) gave on analysis 35 .0 per cent . TiO 2 com-pared with 39 .0 per cent . in the best material .

If in quantity the mineral would be of value as a source ofradium, but probably only a. few pounds could be obtained even ata prohibitive cost .

CHEMICAL ANALYSIS.

Our thanks are due to AIr . W . C . Wheeler for preliminarychemical determinations on the mineral . Mr. Wheeler establishedthe presence of uranium and suggested the separation of titaniumand uranium by hydrolysis, as finally carried out .

The mineral is slowly decomposed by treatment with concen-trated sulfuric acid, or by hydrofluoric and sulfuric acids . It ismore convenient, however, to bring it into solution by gentlefusion with acid sodium sulfate . On dissolving the melt in coldwater, or dilute sulfuric acid, there remains a small residue con-sisting of silica, unattacked mineral, and sulfates of lead, bariumand strontium, which was analyzed separately .

Various methods of analysis were tried, using principally theacid sulfate solution, but the unusual association of elements madethe analysis largely a process of successive approximations . Eachprecipitate obtained was tested for impurities and if an admix-ture was found the method of analysis was modified accordingly .

It was thought at one time that the ammonium carbonatetreatment could be relied on to separate the main constituents,uranium and titanium, but so much titanium was carried into thefiltrate with the uranium in this process that it was decided toseparate the titanium by hydrolysis . The precipitate and filtratewere then further analyzed separately .

For the hydrolytic separation of titanium the sulfate solutionwas treated with hydrogen sulfide, neutralized, freed from hydro-gen sulfide with a stream of carbon dioxide, and finally dilutedand boiled after the addition of considerable ammonium sulfate .'

In one analysis 3.1 per cent, of rare earths was found in thetitanium separated as described and 5 .o per cent . in the uranium

'Hillebrand, W . F ., U . S . Geol . Survey, Bull . 422, 137 lxgro) .

Feb ., 1020.1 BRANNFRTTE, A 'EVV URANIUM MINERAL . 229

portion . In another analysis the total rare earths separated di-rectly, first as fluorides and finally as oxalates, amounted to 8.oper cent.

The filtrate from the titanium was precipitated twice withammonium hydroxide, leaving calcium in solution . The hydrox-ides were dissolved in hydrochloric acid, evaporated nearly todryness, taken up in hydrofluoric acid and the rare earths . filteredoff . After removing hydrofluoric acid with sulfuric acid, pre-cipitating with ammonia, and dissolving the hydroxides in nitricacid, the remaining elements, chiefly uranium, were subjected tothe ammonium carbonate treatment and uranium was finally sep-arated and weighed as pyrophosphate.

The stage of oxidation of the uranium in the mineral wasdetermined separately by decomposition with dilute sulfuric acidin a closed glass tube containing carbon dioxide at 225° C . andsubsequent titration with potassium permanganate . It was as-sumed in calculating the proportion of UO z that all the iron of themineral was in the ferrous condition. The only ground for thisassumption is the fact that iron is more easily reduced thanuranium, so that the existence of any uranous oxide would implythe absence of ferric oxide. However, the state of oxidation ofthe iron cannot be regarded as determined . The coating on thegrains contained some ferric oxide which could only be removedby carefully chipping off the exterior and selecting the jet blackpieces. A determination of iron as Fe O„ on unselected materialgave 3.7 per cent ., whereas the value obtained on the best selectedmaterial was 3 .o per cent ., or 2 .7 per cent. FeO . Iron seems tobe an essential constitutent of the mineral . In the extendedanalysis iron had to be determined in the titanium portion, in theammonium carbonate precipitate, and in the uranium precipitate .

Thorium was determined in the mixture of rare earths by thesodium thiosulfate method, The ignited oxide was white, andpure as far as could be determined . The yttrium earths wereestimated by their solubility in a solution of sodium sulfate . Theywere a buff color after ignition and gave by conversion of theoxides to sulfates, an average atomic weight of 15T, a weightso great that probably erbium or ytterbium or both are present .Lack of time prevented a thorough investigation of the rareearths. No cerium earths could be detected- Water and carbondioxide were weighed in absorption tubes after heating the min-

230

Fg>_xic L . HESS AND ROGER C. WELLS.

U. F.1 .

eral in a boat in a hard glass tube in a current of dry air . A smallcorrection was applied based on the results of blank determina-tions run similarly . No, magnesium, tin, tungsten, tantalum .columbium, molybdenum, vanadium, copper, or fluorine couldbe detected .

An attempt was made to heat the mineral, mixed with car-bon, in a stream of chlorine and make a fractional condensationof the volatile chlorides . A complete separation of the uraniumand titanium was not accomplished, but the non-volatile residuein the boat was found to contain calcium, rare earths chiefly ofthe yttrium group, iron, and a little uranium .

An attempt was also made to detect helium but without suc-cess . On heating 5 grammes of the mineral with acid sodiumsulfate in a vacuum a few cubic centimetres of gas were obtained-largely sulfur dioxide, which was probably generated by theaction of the UO 2 on the sulfuric acid . Nearly all of the gas wassoluble in a solution of sodium hydroxide and what remainedgave only nitrogen lines, as far as could be determined, whenexamined in a Pluecker tube .

The various determinations led to the following results :Composition of the Mineral from Stanley Basin .

(R. C. Wells, analyst.)

C02 2005Fe,O,, ALO.., P,0trace

100 .2Specific gravity, 5 .42 .

I Average molecular weight 350 .

Per cent .

Molecular value ; .SIO, .6OIOTiO,39.0488FeO. . . 2 .9040CaO 2 .9052UO_ 103

038UO, 33.5116Th02 4A .

.015Ce2O,noneYLO.,, etc .' 3.9011Zr0 2 .2oorPbO .2001BaO .3002SrO .IactH2O 2 .0III

0 RR.ANNERITS, -t NEW L ItAN[CM MINERAL .

23 1

CALCULATION OF FORMULA

The following combinations in molecular values seem logical

This leaves Yt 2O;,=o.wi, UO,,= .116, and H,O= .r11 no-grouped. On this basis the mineral may be simplified to :

RO0968.7Yt,Oor'1 .0

RO,055or5.0U0, _i,610.5TiO,50345.7H,0in10.i

Without any further combination this yields the followingapproximate formula :

9 RO. Yt,O,. 5 RO, ii UU, . 46 TiO,, in H,0 .

The figures for RO and UO;, are not very near whole num-bers, but this need cause no disappointment as the whole calculationrests on the assumption that the iron is in the ferrous condition .Although this assumption has certain analogies to support it andis given preference, it would not be entirely unreasonable toassume that part or all of the iron is in the ferric condition . Thequestion cannot he settled experimentally in the presence of uran-ium in two stages of oxidation . If all of the iron is assumed tobe present as ferric iron the following percentages and molecularvalues are obtained in place of those first given

Percent. Molecular

Appropriate grouping now leads to the approximate formula

2 RO. R,0,. 3 ROa. 3 UO,. 1S TiO,. 4 H,0 .

The bases are apparently present as titanates, metatitanates,or uranotitanates, but an exact evaluation of the relative pro-

FeO .040_UO, .038CO, .005CaO .052ThU, .015SiO, .oioBaO .002_Zr( -), OW 1 10, .488SrO Ml -- -

P6O .001 .055 .503

.0(x7

FeONoneFe,0, 3.2020

UO,18.4o68UO,25.1089

232

FRANK L. HESS AND ROGER C. WELLS.

portions of these compounds is obviously very difficult and hardlyappears practicable in view of the uncertainty concerning thestage of oxidation of the iron and uranium . There is more TiO2present than is required to form normal titanates of all the bases,but not enough to form metatitanates without taking some uran-ium as the basic radicals UO and UO 2 . To secure an exact bal-ance any excess of TiO 2 may be reduced to the form of a titanylmetatitanate TiO .TiO, .

The results below are presented for illustration as one of thepossibilities along this line with little to recommend it over othersthat could be given .

Oxide

Molecular

Metatitanate

TiO2value

requiredRO(*R TiOu96YraO011Yt,(TiO,), -033ThOaoi6Th(TiO,),032ZrO001Zr (TiO,)002U0038UO TiO038UO,116UO(TiOa)232Ti0 2070 . . . .

. TiO TiO,070

503

On this basis the mineral may be represented as a hydratedmetatitanate of various bases, thus : (Ca, Fe, UO, TiO)Ti0 3 +(Th, Zr, UO) (TiO,) 2 +Yt2 (TiO,) 3 +H2O. Without imply-ing exact molecular ratios the proportions of these four specieswould be about 6, 8, 1 . 3, respectively . It should be remembered,however, that the stage of oxidation of the iron is unknown andthis ignorance introduces uncertainty in these proportions . Noris it known whether minerals of this kind should be consideredas mixed crystals, solid solutions, or salts of complex acids, al-though in one of these suppositions may lie the correct explana-tion of their composition .

Analyses of the known complex uranium minerals have beenarranged ill the tables following so that the uranium content in-creases progressively toward the end of the series. The newlydescribed mineral from Idaho is designated as brannerite .

It will be seen that the new mineral contains more uraniumthan any other except the pitchblendes. Unlike most of theothers it contains no tantalum or columbium and is very highin titanium .

Fd, ., 11)20.1 13RANNERITE, A NEW L R.AN Ll - \I MINERAL .

Comparative Analyses of the Complex Uranium Minerals .

(Arranged in the order of their uranium content .)

Ris6- Yttria- Zirke- Mic o- Yttr9-Name

rite

lite

lire

Iite

cams-lite

Page, Dana's . .

APp.3 .

512

App. 1, 728

739Systemp.68

p 75Analyst

. . . 0 . Hau- J . B .

G. T . Dun- Ram-set

Mack- i Prior

fling-

mels-intosh ton bar,

Cry ..F9vn • .

A

I

I

O

0Isot . or b1f.s . . .

lint

Isot.

Isot .

fact . 1 lsot .

Isot tobif .

Indices . .

2 .05

r .7581

2.19

1.930

2 .15

2,Q1 .818Sp . G . . .

4.575

4.74 1

5 .656

5.4"5 y .8043

. . . .

4 .0943

46 a5

'1'raw, . .

4 .00

. 68 .

.

race

7_69CbsOs . .

. . . 36 .21

Presen

36 .68T1o, . .

6.00

14.95

. . 49 .72

21'QU

. . .O2-

Undet .

1 .401 .61

1 .98

0 49U0s 0 .83

1 .59

0 .64

2 .14

3 .03Ceso1 . .

88,

1 .86

2 52

o.17A

2 .22

2 .92

~~ J2IDi.La)sOi

. . . .

".94'Y20s . .

j36.28

46. .501

0-21?

n 23

5

25 .67 ~117 .n

9.1pT iOh02

. Under .

12.00

7 .31

8 .75

c .6r

5 .m

. . . .ZrOs 52 .74

15 .30

2.61Ga0 .

1-03

o 6o

r0 .22

11 .80

5 .73 1

1

4 .12 - .

2 .05M40 0 .22

1 .01

' T1nce

0.22

0 .05W02 .

5. .

. . . .

1 . 03

6

187

.7

0 .Sri. Un dr.

ndr

1 .05

11

u39

. a n.o8

FCU . . 2 61 1 .81 7 .72 3 Bo 5 .63 2 .04Fe202 . .

1 .2 r

I

)

1 . .' 3

9 "-

TraceMno . .

o 77

. . .

n 1P60 .

Under

0 85 X

1' 48

- . . .H20- I

7-1

1 ' 79' _ .' my

6.31

1.36

1 69

3 .19

% .

o.p9d

. . . .

. . . .

0.68

-race~AIsO3 . .

n-8

n55Sill

. .

29 .1 ;Na-O..

2 .86

. .

, . .0 .16h20 . .

0.29

0 .062.83

•T racyBeG . .

0.34

.69

98.95 coo .57

4, a .morphnvs ; I . isometric : 0, urthorhom-hic, '1', tetragonal,

' Isotropic ar blrefdngent Most of thedeterminations of oprIcul properties aby E . S . Larsen and were not made nn

e material.(Cs., T.u, Nd) .O1

I S2, f;e•

At . wt 162 .a.rths

2 . . 7 per cent- at . .1103

Yttro- Prier- Nail-cite ite gite

App . 2' All . 2,ii App . 2,p .112

y 73C, . T . Haga

War- Prior

O

Thut .

109-73 19u-48

35 . 5.3n per cent ., I t . wt . r 53C . 450 per cent, at . wt. 114.9D . 14 .03 per rant ., att wt 1m .

gnitinn" IC O, ODsOaCOs

j Ta2O, a ht . a pcr cent .UO

1 Y,Os abt . 1 per cent .Li2O -

233

Sryy-lite

731W. G .Brown

Isot .

2 .064 89

48 .661

3 47.

377 .987 .94 1

234

FRANK L. IIESS AND ROGER C. WELLS.

Comparative Analyses of the Complex Uranium Minerals .-Continued .

[J- F . i .

(Arranged in order of their uranium content .)

NearName

Samar-skit,

Hiet-mite

Blom-Anus-dine

P yro-chlore

Fcr u-Kemote

NearSamar-skite

vie-tingho

fiteI glii

kiteDeb,ren-2te

Page, Dan.',I

Ann . 2, 726 APP- 3, App . 2,'stem .,

740

74r17 730 740

740 A 34Analyst

Crys. Form,

Hill, I A. E.brand 1 Nor-

denskibld0

W .Blom-strand

0

Ram-mels-berg

I

W. H .Sea-mooT

W. F .I Hill,brand

A .D.-

amour

A

Hul8m-

quest Sterha

UIsott or bit . . . . uniax- Isot .

Isot .

Isot Usnallyl . . .0

. . . .lal (i) 'sot . .

Indices W=2.3o 2 .14 7 .96

2 .591 .i

E - 1 41)SP .G. 6 .x8 5 .82 4 .82 4 .22 5 .6

1

6 .19 5 .534 .93 4 .

4 .08

19.34Cb1O5 27 .77

Itia-qz23 .35 58 .27 4378 27 .56 51 .00 23 .67

'710, ^ . . . . . 27 .39 5 .38 . . . . . . . 1 .84 29 . 0 66 .03UO, 4 .02 4 .87 5 .35 5 .53 • . . . .81 8 .85` 1 .86 9 .87-UO1 . . . . . . . . . . . . . . 6 .20 7 .37Ces01 . . .(Di . Ln),Os

0 .541 .8o

1 .07 2 .48 . ..5 .5! .,66

3 .4911 411 .44 1 1 57 L

Y'O' _ . 6 . .i e .19' )25 .62 . . . . l. 7 21 5 .64.

. . .'6 .57

1 . . 06 x4 .63Eo,O I,71 ~ 0 .82 . .

)4Oz-

. . . 3 . 64 . . . . . q 33 4 .96 3 .19Z702 2.29 1 .33 . . . . . 3 .10 1 96Nigo o .27 4,26

0 260 .850 .15

10 i

0 .65 1 .61o .1r

4,860 .83

WO

. . . 2 .25.

". . . . . . .

0 .76 5 .51. . . . . . .. . .

. . . 0 .95 j 8.6 1-43 0 .82

. . . . . .

. . 4 33. . . .FG

8 .77 80.1-43 5.53 1 .81 0-39

23 .00 4a5-,O0 . 78 . .

. . . . .

. . . 8.90 7 .51McOs. .0 78 3 32

, 800.77 9

2 .67P50. . . . . . .

o . 8LO 0 .72 0 .546 1 .97 . . . . . .

. . . . . . . . 0 .9" 2 .56 3 .94

1 .30 1 .06X. . .N

..aO

0 .¢v". . .

. . . . . . . . .0 .10 0

.49d0 .00K O

0 .17 . . . . . . . 0 .18100 .31 199 .37 99 .75 99 .11

Includes some Ti02 2 MnO and ZoOZnO 0 05 ^ (K . Li . Na),OiLi, 'a),0 0.24 ' 13202Coo 7 Ignition

^ZnO 0.09 "MmOsSiOs o.4o

UOFcO andPrecipitated by His 1 .o6

A1,O, 0 .74Ignition 1 .53 SiO 8 .75F 3.'S ^ State of oxidation not determined .

Ieb . .l920.1 BRA-NNERTTF, A- -\T]-N%- URANIUM MINERAL .

Comparative Analyses of the Complex Uranium Minerals .-Continued .(Arranged in the order of their urnniurn concept .)

Plum-

_ Alter- I hatchEux - Eux "matoh edSam etto-

1

AmName

1te

rte

skvce

11ce

romte bite -.

„rskite

b~ieepabn flam

742

739

,pp.

74.

74-

727

AP p'.Analyst

Rave- Ko 'g Housed \orders W. 13 O . D. C. W P ,aoels-

and

sk161d

Sea-

Allen Bom-ber.

Finkh

strandCry. Form . . . .

O

0

A Mss- 0

I

0

0?I've

isnt, or hi`L.- .

Is9t

Isc[Indices

z . a4

e. z4

¢ .1n.25Sp.G . .

. .

1

4.99

5 .193

5 .96

4-803 ' ;-a46

4,8{3•

sO, . . . 13.89 8GbCiOz

2 73

S3 39

56 la

46 . E5

3- .43T30

'7.7o 3.aUO . . . .

-to.5o^

12 11

13 .48

13 7a

X1.13,•

,D, L ,

u.6 a •

-85

° aa1aU,

IE Oo

25.64

14 CO

1 911

14.26 l14 56Th2_ . .

1.34

. . .

n .on

. . .•

Trace 2 .96•

0. 0.09 1 36 - 3 .05 4,67MgO . . . .

o .1z

. .

. . . . .•

& o-13 11 4n 10.30- F,(1. 8 98 .7 8 99 1 7 n9 219Fe'(), --

a .63

66

-MnOTruce

. .

o 28,PhO . .

0,20

1

7-6a

CraccH2O--

3 90

z .4a

o.30

6.38

9.55

4 49•

. . . 0.74° - o.5rzr 0 .31*AI-O .

z . 1

u.23

. . .

1 00 71

98.77 198 57 'On .2Iron 1o

00 .67

08 .55

Miller,uwat .,K,i,hhd W.,

r N:, Tie- and

.cceof

eniSovt She, -

COrz . .

0.19brooke township, Ontario : .Am . lour .

MnOSci., vol . xhv, PP . 243-244, 1917.

CuOTraceSame of analyst not given . Analysis

, LOmade at Impenal institute, London,

^ MnO, MgOEngland .

' COOI L,O,

% Anhydrous mineral1Gc La)cUt etc .

1 SiO2Sit}

Ignition•

Sp.G. . 5 .77

Isot .

Itot .1 .98

z . .34 .77 1

5.7'

3 .074 33 19to 33

A 9017 09 34-24 18 13

34 80 1 61

4 .90112.28,

i9.4o15 15

q 501 . 49

t S6

10 n 604 0013 .46

7.10

0u. . . .

x .37

z . ;o 3 35

.1-53

0.17

3 35

x .500.15

o Ir0 16 1 o-So

38 8 602

. .o a0

. . . .

40

8 .19

12.40

0 28

a .u0 .160251 1100 .50

236

FRANK L . CIESS AND RuUER C. WELLS,

[J.F.1,

Comparative Analyses of the Compex Uranium Minerals.-Concluded .(Arranged in the order of their uranium content .)

° At . wt. 1-4.1s IIgnnstil .

ition•

ThOs, CesO,•

La O,, Y10,P.O,UOPrecipitated by HisSh e's., Edward S ., Pdbarite,

newmineral from the Pilbara Goldfield :Jour . Nat. Hist. and Sri . Soc . of WesternAustralia, vol. iii, p . 131, roll .

Lacroix, A., "Min€ralogie de 1. France etde ses Colonies," vol . v, PP . 93-94 . 1913

•

Mol . wt. 3501 BaO 0.3SrO _

. . . . 0 .1COv 0.3PsO TraceDet . as NZoO 0.44Pros 0.22As,O, 0.43CoPeSs 0.12FeS n .24

P.],- 5 Mack- Blom- Pilbar- Bran- Pitch- Trani-Name class -Esit e intosb-

itestran-dice itet

-~

Beteaf-3 nerite blende nite

App . 3 . App. 1,Page, Dana's. . .System . .

745AnalystMack-

p.69P2sani

p . 4qHille-

74 6

Lind- Sun, Piaaui Wells Hille-891 891

Hills-intosh brand strum son brand brand

Cry., Form 1 T Mas-dye

A I I I

lent . or bitIsnt . Isot . Isot. Isot Isnt . Isot. Isot . Opaque OpaqueIndices1.70 1 .94 1 .77 2_14 1 .74 1 .93 2 .30Sp .G4.97- 5 .24 5 .438 4 .17 4 .68 4 .475 5 .42 8 .07 9 .59

5 .04 4 .25TesOs . .

3 70 - 0 47 Trace . ., . .Cb,Os . .

X9 3

45 8o . . }49 .76 32 .10 . .

.2851

UOs . . . .

.

26 201 . 7t 39

22 40 123 .68- 117-b0

10 .3 58 51

57.43UO2.-

19.47 a, 09 28 .60 33 .5 25 s6 26 .48Ce1Oz . . 45 102

0 9 I . . 0 .22

0.25(Di, La)s0

. . . .

}0 a0 . . . . . . }1 .xo . . . . . . . . .

0.13Y,O 23 I S6 . . . 049 39 0 .20ThO . . 34 5 4 1 9 79ZrOi 9 88 0 2 7 59CaO 0 .68 . . 0 59 3 .4S 0 57 1 .61 q 0 84 0 .09Mao . . .SnOs

.

. . . o -0 0 .16 a . . . . . . . .

Fe0 . . 2 .47 06. . . .to .

15 3 .33 2 .9 0 32Fe.0> 0.18 . .

. . . . . . . . 0 .20r.38 Trace . . . . . . 0 .40

MoO . . . . 0 .04 Trace 0 .25 . .

. . . 9 16PbO 0 .46 7.35 3 .74 . 17 .26 . . . . .

. 0 .2 0 .70 3 .264 .46 x245` 0.50 7,96 3 .50 5-a0 2 .0 1-96 e,61

HsO {- . . . . . . 4 .16 . .

. . . .4 .31. .

. . . . . .0 .15". . . . . . . . . . . Trace . . . . . Under .

0 .12^ . . . . . 0 .671 0,,22 [ .087 . . . . . . .oe

..45" 9 .70 1AIsOa 0.74 . . . . . . 0 .-1 0 .15 Trace . . . . . .510, . . . .

. . . 1 .01 . . . 13 9 . . . . . . . 12 72 . . . 0 6 2 79 0 .16LhO . . .NasO ._

. .. . .. . 0 .68 . . . . . 0 04 . . . . . . . . . . . . .

K,O_ 0.30 0 .4z . . . . . . . 0 .09 . . . . . . . . . . . . . . . .

97,96 99 .6 . 96 .50 90 .32 99 .56 9939 100 .2 90 .95 99 .49

Feb ., ig20 .1 BRANNERITE, A NEW URANIUM MINERAL .

237

The only other minerals having the same general qualitativecomposition are zirkelite and delorenzite, and to make com-parison easier their analyses are repeated .

Analyses of Zirkelite, Delorenzite, and Brannerite .

ZirkeliteIsometric

Specific gravity'

4742TiO,14.95UO,x .40UO., .Ce,O,52Y,O,0 .21Th0 27.31ZrO252.89CaOMgO0.22SOO,FeO7 .72PhOH,O =1 .02 (ign .)Na,O1 0.79SiO,_'RaOSrO. . . . . .Co2Fe,O,A1,O,P,Os . . . . .

• State of oxidation not determined.

The uranium in zirkelite is almost negligible and the quan-tity of zirconium present puts it in a class by itself . The analysisof delorenzite makes the mineral appear almost suspiciouslysimple in composition, only five metals being determined, but therelationship to brannerite is closer than that of zirkelite . How-ever, the quantity of uranium oxide is less than one-sixth thatof the titanium oxide, but in brannerite the weight of uraniumoxides is greater than that of titanium oxide and is more thanfour times as great as that in delorenzite.

The new, mineral seems worthy of an individual name, andwe therefore propose to call it brannerite after Dr. J. C. Branner,formerly head of the Department of Geology and Mining andPresident of Stanford University .

Brannerite may be described as a complex titanate of uraniumwith smaller quantities of rare earth and other metals, in whichthe weight of uranium oxides exceeds that of titanium oxide .

VOL . iSg, No. 1130-17

Delorenzite

BranneriteOrthorhombic

Undetermined

4 .766 .039 . 870

14 63

4334.254

5 .4239010 .3,33 5

394.10 .22 .9

2 .90 .22 .0

o .60 .30 .10 .2