GEOLOGICAL SURVEY CIRCULAR 2M 

SPECTROGRAPHIC IDENTIFICATION 

OF MINERAL GRAINS 

By J. N. Stich 
;.hii8 .11 . · ·r& 
UNITED STATES DEPARTMENT OF THE INTERIOR 

Oscar L. Chapman, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CIRCULAR 234 

SPECTROGRAPHIC IDENTIFICATION OF MINERAL GRAINS 

By J. N. Stich 

This report concerns work done on behalf of the 

U. S. Atomic Energy Commission 

and is published with the permission of the Commission 

Washington, D. C., 1953 

Free on application to the Geological Survey, Washington 25, D. C. 

SPECTROGRAPHIC IDENTIFICATION OF MINERAL GRAINS 

CONTENTS 

Page 

Abstract..................................... 1 

Introduction. . . • . • . . . . • . . . . . . . . . . . . . . . . . . . . . . . 1 

Discussion. . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . 2 

Methods..................................... 2 

Procedure . . . . . • . . • . . . . . . . . . . . . • • . . . . . . . . . . . . 3 

Page 

Results and tables ........................... ~ 5 

Future program.............................. 5 

Literature1 cited. . • • • . . . . . • . . . • . . . . • . . . . . . . . . . 5 

Composition of standard 

solutions...... . . . . . . . . . . . . • . . . . . . . . . . . . . . . . 14 

TABLES 

Page 

Table 1. Sensitivities on the basis of 1-mg samples for the elements determined by the 

microqualitative method ..•...••.•...••••......•..•• ~ ......•.• -. . . . . . • • . • . • . • . . . • . • . . . . . . . . . . 7 

2. Wavelengths and sensitivities of the analytical lines used in the microqualitative method............ 7 

3. Comparison of chemical quantitative and spectrographic qualitative microanalyses of 

samples of uranium minerals ....•.••.•................•...............•.•.....••••.•..•••.. 11 

4. Mineral identifications accomplished by agreement of spectrographic microqualitative 

analyses with data from X-ray diffraction patterns . • . . • . • . • • . . . . . . . . . . . . . . . . . • . . . • • • . . . . . • . . . . 12 

ABSTRACT 

A qualitative spectrographic method of analysis 

of single mineral grains, impurity inclusions, X-ray 

powder spindles, and other small samples weighing 

1 mg or less is described. Samples weighing as little 

as 0. 01 mg have been analyzed. Where 1 mg of 

sample is available, the accuracy of the method 

approaches that of a semiquantitative! method. During 

a 10-month period, 20,000 determinations of 69 

metallic and metalloid elements in more than 300 

small samples have been made with the method. In 

conjunction with petrographic, physical, and X-ray 

methods, these determinations of chemical composition have been useful in establishing the mineral 

identity of small single grains. A direct-current arc 

is used. The use of a standardization solution that 

includes only one element per plate greatly facilitates 

the selection ot: reliable analytical lines. A small 

carbon electrode cut from graphite stock 1/8-in. in 

diameter is used; this is convenient for the loading 

and arcing of X-ray powder spindles. The mediumsize quartz-prism spectrograph is preferable to a 

grating instrument for qualitative microanalysis as its 

complete spectrum coverage for a single exposure 

includes the most sensitive lines of the alkali elements. 

lliTRODUCTION 

In connection with the investigation of radioactive 

raw materials conducted by the U. S. Geological 

Survey on behalf of the Atomic Energy Commission, 

a large number and variety of samples are received 

for spectrographic analysis. 

1 

Among these samples are many that are available only in 1-mg amounts or less and consist chiefly 

of mineral grains and impurity inclusions hand-picked 

under a petrographic microscope from many rocks 

and ores being studied. Because these small samples 

are ·composed of grains selected individually and may 

occasionally include but one grain each, they are also 

referred to as "single-grain" samples. 

Although many of these grains can be identified 

on the basis of such properties as crystal structure, 

index of refraction, hardness, specific gravity, and 

X-ray diffraction pattern, frequently their chemical 

composition must also be determined in order to 

establish their mineral identity (Lee and Wright, 1939). 

Owing to the small size of the samples, which 

generally limits the duration in the arc of their 

characteristic spectra to a few seconds or less, the 

application of a visual spectroscope (Peterson and 

others, 1947; Jaffe, 1949) is restricted to the determination of one or two major elements at a time. Also, 

unless larger samples are used, many elements, 

such as arsenic, boron, and phosphorus, whose 

principal emission lines occur in the ultraviolet range 

not visible to the eye, cannot be detected with the 

spectroscope. 

The use of the more sensitive spectrograph, 

however, permits the rapid qualitative analysis of 

single-grain samples for a complete range of metallic 

and metalloid elements in concentrations down to 

0.1 percent and lowerr Another advantage of the 

spectrograph is that, in the form of a spectrogram 
recorded on a photographic plate, it produces an 

objective and permanent record of the analysis of a 

sample. 

The a:uthor is indebted to his associates of the 

Geological Survey for their help and cooperation, 

particularly to A. W. Helz for his invaluable technical 

aid and to C. L. Waringwhose suggestions contributed 

materially to the scope of this paper. Special thanks 

are due also to C. S. Annell for the use of his standard solutions, to Alice Dowse Weeks and Mary E. 

Thompson for providing many of the samples, to 

Evelyn Cisney and Joseph Berman for the X-ray diffraction pattern checks, and to A. M. Sherwood for 

most of the chemical microanalyses. 

DISCUSSION 

In addition to inclusions and small single grains, 

the types of samples analyzed included magnetic 

separates, fragments of\ mineralized wood, placer 

sand, sediments, chemical precipitates, distilled 

water residues, furnace slags, and corrosion products. 

Samples weighing as little as 0. 01 mg were analyzed. 

During a periop of ten months, 20,000 determinations 

of 5g metallic and metalloid elements (table 1) in 

more than 300 small samples were analyzed by the 

method. 

The single-grail]. samples are received in the 

form either of the grains themselves or more often of 

ethyl cellulose X-ray powder spindles containing the 

grains. 

The practice of arcing X-ray spindles rather 

than duplicate samples of the grains is advantageous 

because it reduces the amount of separation work 

required and also permits the data from the spectrograms of the ar-ced spindles to be checked directly 

with that from the X-ray diffraction patterns previously obtained. 

The spectrographic results are reported 

qualitatively as 11major, 11 minor, 11 and 11 trace, 11 corresponding approximately to brackets of 10 percent 

and over, 1-10 percent, and 0.1-1 percent concentrations. With single-grain samples and X-ray 

spindles these results are used specifically (1) to 

confirm the cherr1ical compositions of minerals tentatively identified by their X-ray diffraction patterns 

and other properties, (2) to determine impurities 

in the minerals,and (3) to differentiate between 

minerals producing similar X-ray diffraction patterns, 

such as metatorbernite and metazeunerite. If no 

patterns are obtained, the spectrographic reports 

aid further study and purification work. 

Some of the minerals that have been analyzed 

and whose identifications have been confirmed by 

checks of the spectrographic results with the X-ray 

diffraction patterns are: 

Uranium-bearing and rare-earth minerals 

Allanite 

Autunite 

Bastnaesite 

Beta-uranotil 

Brannerite 

Carnotite 

C uprosklodowskite 

Cyrtolite 

Euxenite 

Florencite 

Huttonite 

Kasolite 

Parisite 

Phosphuranylite 

Rauvite 

Saleeite 

Sa mars kite 

Sklodowskite 

Soddyite 

Tho rite 

Torbernite 

Tyuyamunite 

Uraninite 

Uranocircite 

Uranophane 

Zeunerite 

Miscellaneous minerals 

Apatite 

Apophyllite 

Azurite 

Barite 

Biotite 

Calcite 

Cerussite 

Chrysocolla 

Conichalcite 

METHODS 

Franklinite 

Gibbsite 

Goethite 

Halite 

Hematite 

Hewettite 

Hydro mica 

Ilmenite 

Kaolinite 

.The spectrographic method of microanalysis 

initially applied to this wide variety of minerals 

utilized a 220 d-e volt arc at 10 amp and an Eaglemounted 3-meter grating spectrograph. The d-e arc 

was chosen because, generally, it gives the highest 

sensitivity (Nachtrieb, 1g50). As the method involved 

a determination of major and minor elements in very 

small samples, the use of the same excitation con--· 

ditions favorable to the determination of trace elements in larger samples was indicated. 

The standards used· consisted of four mixtures 

containing 10 different elements each, prepared in 

2 

Magnetite 

Melanovanadite 

Montroseite 

Orpiment 

Pyrargyrite 

Pyrochlore-microlite 

Quartz 

Realgar 

Rutile 

Smal ti te -cloanthi te 

Soda-niter 

Sphalerite 

Talc 

Topaz 

Vosenite 

Zircon 

1, 0. 1, and 0. 01 percent series of concentration, 

with silica as the base material. Because the use 

of 1 mg amounts of each of the standard mixtures in 

the preparation of the standard plates was based on 

taking 1 mg of the unknown sample, 10 perc_ent 

standard spectrograms were obtained by using 10-mg 

amounts of the 1 percent mixtures. The arrangement 

of the elements within each mixture followed that 

described by Van Tongeren (1g38). 

This procedure had two serious limitations: 

( 1) as the exposures were made in the generally 

useful range of 2450-3850 A, the single-exposure 

spectrum coverage of only 1400 A did not include 

the most sensitive lines of the alkali elements; and 
(2) the complexity of the spectrograms of the 

1 percent standard mixtures, that made it difficult to 

select and identify the reliable analytical lines for 

each element. 

The disadvantage of limited wavelength coverage 

for a single exposure applied also to the Wadsworthmounted 21-ft grating spectrograph. With its grating 

set to cover the ultraviolet range down to 2250 A, the 

upper wavelength limit effective is at '4750 A, which 

falls short of the 5890-7700 A region where the persistent K, Li, and Na lines are located. The detection 

limits of K and Na with the grating spectrographs set 

in the ultraviolet range are only about 10 percent on 

the basis of 1 mg of sample. 

When a medium quartz prisrE spectrogra:ph 

accomodating 14-in. plates and permitting a singleexposure coverage of the entire range from 2080 to 

10,000 A became available, the method was transferred to this instrument. The d-e arc was retained. 

At the same time the solution standardization procedure described by Waring and Annen (1951) was 

adopted (see Procedure). 

Because the complete spectrum coverage of the 

prism spectrograph for a single exposure makes ava.ilable 

the K lines at 7665 and 7699 A and the Na lines at 5890 and 

5896 A, it is possible to detect K and Na as low as 0. 1 perceht in 1 mg samples. This is a distinct advantage, especially in seeking to differentiate between various uranium 

minerals, such as carnotite and tyuyamunite (table 4). 

In addition theCa lines at 8498, 8542, and 8662 A are available. As many of the samples submitted for analysis contain high concentrations of uranium, these lines are useful 

because their intensities are not depressed by uranium 

nearly as much as are those of theCa lines at 3159 and 3179 A. 

The use of standard solutions, involving only 

one element per plate and producing relatively simple 

spectrograms, greatly facilitated the selection of 

reliable analytical lint?S (table 2). The accuracy of 

the method depends upon the utilization of the proper 

lines (see Res_ults and tables). 

Checks of many of the X-ray diffraction patterns 

and some chemical checks, obtained in tho'Se few cases 

where enough sample was available for a chemical 

rr.icroanalysis, have been made (tables 3 and 4): The 

agreement of the c'hemical and spectrographic results 

are adequate for purposes of mineral identification. 

It has been our experience in applying the method that 

the agreement is likely to be good for sarr1ples weighing about 1 mg; for such samples the results may 

become semiquantitative rather than qualitative. 

Although the standardization of the method is on 

a semiquantitative basis (Waring and Annell, 1951), 

the results have been reported only in qualitative 

terms, defined in Discussion, for the following 

reasons: (1) many of the samples weigh les~ than 

1 mg, necessitating upgrading of the element concentration estimations with respect to the standard 

spectrograms that are b.ased on 1 mg of sample; (2) 

in the case of the X-ray powder spindles the exact 

weights of the samples are not known; (3) the omission 

of a flux (Procedure) increases the possibility of the 

sample matrix influencing a determination; and .( 4) 

the number of c;hemical checks is insufficient for a 

statistical study of the accuracy of the method. 

3 

The dispersion of the medium quartz prism 

spectrograph used is 4. 6 A/mm at 2500 A, 8;4 at 

3000 A, 17. 2 at 3500 A, 21. 5 at 4000 A, 42 at 5000 A, 

75 at 6000 A, and 111. 5 at 7000 A. The low dispersion 

from 5000 A up is not troublesome because this region 

is generally free from strong lines other than those 

of the alkali elements which are readily resolved. 

Another medium quartz prism spectrograph was 

available having a lower dispersion of 8. 7 A/mm 

at 2500 A, 14. 8 at 3000 A, 22. 5 at 3500 A, 33 at 

4000 A, 61 at 5000 A, 100 at 6000 A, and 167 at 

7000 A. This spectrograph permits a complete 

spectrum coverage for a single exposure on a 10-in. 

plate. Tests were made to determine whether this 

instrument was also applicable to the microqualitative 

method in spite of its lower dispersion than the first 

spectrograph. Under similar excitation, optical, 

and exposure conditions (Procedure), a plate was 

exposed to 1 mg samples of four minerals producing 

complex spectra (carnotite, calcium ·uranylvanadate, 

brannerite, and allanite). Then, utilizing the solution 

method of preparing the standard electrodes, standard 

plates were made for the elements Ca, K, Na, Fe, 

Ti, Si, Th, U, V, Ce, La, and Y, constituting the 

major and minor components of these minerals. The 

series of spectrograms obtained for each· element 

represented concentrations of 10 percent, 1 percent, 

and 0.1 percent based on 1 mg of sarr1ple. By means 

of these standard plates, the positions of the analytical 

lines were readily determined. In spite of the low 

dispersion of the instrument, no difficulty was experienced in identifying these lines in the complex 

spectrograms of the 11 unknown11 samples. The analytical results obtained checked with those previously 

reported for the same samples tested with the prism 

spectrograph with higher dispersion. It is thus 

indicated that, in conjunction with the solution standardization procedure, the lower dispersion medium 

prism spectrograph also can be used effectively for 

the qualitative analysis of single grains, X-ray 

spindles, and other small samples weighing 1 mg 

of less. 

Prior to adopting the solution method of 

standardizing the medium quartz prism spectrographs, 

the use of pure minerals as standards had been considered. For the following reasons, however, it was 

adjudged impracticable: (1) the v~ry·large number 

of mineral standards required; (2) the difficulty of 

obtaining pure minerals; (3) the problem of diluting 

these minerals to obtain sets of spectrograms corresponding to various series of decreasing element 

concentrations; (4) the presence of impurities in the 

unknown samples analyzed and the fact that the 

samples are often mixtures of two or more distinct 

minerals; (5) the need for an independent and allinclusive procedure of.analysis in cases where the 

sample is a newly discovered mineral in the proces~ 

of identification or where it is a chemical precipitate 

or other material; arid (6) the complexity of the 

resulting spectrograms thus again making it difficult 

to select reliable analytical lines. 

PROCEDURE 

As. described by Waring and Annen (1951), the 

solution standardization procedure involves the preparation of a standard plate for each element, each 

plate showing a series of spectrograms representing 
element percentages decreasing in mult.iples of ten 

from 10 percent to 0. 0001 percent, based on an unknown sample weighing 1 mg. 

The standard solutions are prepared from 11C. P. 11 and "Specpure" grade chemicals usually to 

give a concentration of 10 mg of the element per milliliter of solution (for the compositions); 0. 01 ml of 

each 10 mg/ml solution is equivalent to 10 percent of 

the element in a 1 mg sample. These solutions are 

consecutively diluted so that 0. 01 ml of each is then 

equivalent to 1. 0, 0. 1, 0. 01, 0. 001, and 0. 0001 percent of element based on a 1-mg sample. 

In the preparation of a series of standard electrodes representing 10-0. 0001 percent element concentrations in a 1-mg sample, the bottoms of the 

electrode craters are first sealed with paraffin added 

in the form of a few drops of a 1 percent benzene 

solution of the wax (Waring and Annell, 1951). Then 

0. 01-ml aliquots of the 10-0.0001 mg/ml solutions are 

introduced into the electrodes, using a micropipette 

equipped with an extension whose tip fits into the 

craters. The electrodes are dried in a brass holder 

placed on an asbestos-covered hot plate adjusted to 

a temperature of approximately 100 C. -

Provision of reference spectra for the standard 

plates follows the arrangement used by Waring and 

Annell . (1951). Before arcing of the electrodes in: the 

order of decreasing element concentration, a spectrum 

of iron is recorded on the plate. Following arcing of 

the last standard electrode, a spectrum of 1 mg of 

aluminum alloy (Alcoa aluminum standard no. 874) 

weighed out in the form of filings is also registered. 

The spectrograms are 2. 3 mm high and positioned so 

that the bottom of one spectrogram nearly coincides 

with the top of the succeeding one. The arrangement 

is similar for the unknowns.except that the number of 

spectrograms included between the reference spectra 

is limited to two or three. In running a suite of unknowns, a half dozen such series of spectrograms and 

reference spectra can be recorded on a plate. 

The concentrations of elements in the unknown 

samples are estimated by visual comparison of certain 

lines of these elements in the unknown spectrograms 

with those on the standard plates. Where the sample 

weight is less than 1 mg, the estimations are upgraded 

by the necessary factor. If, for example, the sample 

weighs 0. 5 mg, the preliminary estimations are 

multiplied by two. The plates are read on a viewing 

desk under a microscope or on a viewing box with a 

magnifying eyepiece. 

Besides furnishing reference points additional 

to those provided by the iron spectrum, the aluminum 

alloy spectrum serves as a useful check on exposure, 

emulsion speed, and plate processing. The Cr line 

at 2780. 703 A, in particular, is a sensitive indicator 

of the optimum conditions. When these are being 

maintained, the intensity of the line falls within a 

transmission range of 80 to 95 percent, measured 

with a Jarrell-Ash microphotometer. The other 

components of the alloy--Cu, Fe, Mg, Mn, Si, Ti, 

and Zn--present in known trace amounts also produce 

lines whose intensities may conveniently be used for 

supplementary reference when estimating concentrations of thetSe elements in the unknowns. 

4 

The power for the d-e arc is supplied by a fullwave mercury vapor rectifier (220 volts direct current 

and 15 amp maximum). An inductance for giving 

smooth operation of the arc and a rheostat for controlling the current are used in series with the arc. 

The rheostat has three fixed values, 74, 38, and 

19 ohms, producing three possible arc currents of 

approximately 2, 4, and 9 amp. The value of the inductance is not critical; in this case an old 7. 5-kw 

autotransformer is used for the purpose. 

The standard electrodes, the aluminum alloy 

samples, and the unknowns are arced at 9 amp. The 

iron arc is operated at 4 amp. All arcings are with 

a gap of 4 mm for a period of 60 seconds at 8 percent 

transmission controlled by a rotating-sector disk. 

The slit width is 10 microns, with the arc focused on 

the collimating lens. The emulsion used is Eastman 

I-L, developed in D-19 for 4 minutes at 18 C .:!:.l/2 C. 

The samples are weighed on a 5-mg torsion 

microbalance and generally range from 0.1 to 1 mg. 

A microfunnel drawn from 7-mm glass tubing is used 

t-e transfer the samples from the detachable balance 

pan to the electrode craters. Spindles are transferred 

directly by sliding them off the pan. 

The weight of sample in a spindle is determined 

approximately by subtracting from the total weight of 

the spindle and its contents the estimated weight of 

the spindle alone. Spindle weights can be estimated 

to within about+ 0.1 mg by comparison with an available series of previously weighed blank spindles. 

A supplementary criterion for estimating the weight 

of sample in a spindle is the fact that usually the 

weight ratio of spindle to sample is about 1:1. As 

spindles and their contents .usually weigh from 0. 5 to 

1 mg, the actual sample weight ranges from 0. 25 to 

0.? mg. 

No powdered graphite or other flux is added to 

the sample because the nature of the samples precludes effective mixing. 

The determination of fluorine in the samples of 

low calcium content requires a separate exposure 

(Waring and Annell, 1952). Two-tenths of a milligram 

of calcium as calcium chloride "in solution is added to 

the electrodes that are dried before introduction of 

the unkri.own samptes. The addition of calcium causes 

the formation in the arc of the calcium fluoride 

molecule that emits the bands used for the fluorine 

estimation. 

The carbon microelectrode used has a 

deep, thin-walled, cylindrical crater that is 

convenient for the loading and arcing of X-ray 

powder spindles, in addition to other materials. 

The half-inch depth of the crater corresponds .to 

the length of the average spindle, thereby 

eliminating any necessity for ·cutting it up. This 

depth also tends to prevent mechanical loss 

during arcing of the sample when it consists of 

refractory grains. After fusing, the sample adheres to the graphite and burns away to completion along with the carbon, thus fulfilling an 

essential requirement of qualitative analysis 

(Nachtrieb, 1950). The dimensions of the electrode, 
cut and drilled with a Bausch and Lomb electrode 

shaper, are as follows: 

l/8-in. spectroscopic 

carbon rod. 

Crater, outside diameter ... ' .• Crater, inside diameter •.•.... 

Crater, depth .•...•.....•..•. 

Outside shoulder below 

crater rim. 

1 3/4 in. long. 

0.090 in. 

0. 052 in. (no. 

55 drill) 

l/2 in. 

5/8 in. 

The upper electrode, the cathode, is .cut from 

a l/ 4-in. spectroscopic carbon rod. Its arc end is 

hemispherical with a 0. 06-in. radius. Tests showed 

that this upper eleGtrode produces less background in 

the spectrograms than would be caused by electrodes 

of smaller dimensions. · 

The iron arc arrangement consists of a l/ 4-in. 

iron rod as the lower positive electrode and an upper 

carbon electrode the same as that used for the 

samples. 

RESULTS AND fABLES 

Tal;>le 1 lists the sensitivities on the basis of 

1-mg satrtples for the 69 elements determined with the 

method. The values are those indicated by the solution standard plates on the basis of 1 mg of sample. 

Where less than 1 mg of sample is available, the 

sensitivities are reduced by a factor equal to that applied in upgrading the estimations of element concentrations (Procedur.e). Interference by the lines of 

other elements also decreases the sensitivities listed. 

For example, where uranium is a major or minor 

component of a sample, the thorium line at 2837. 299A 

cannot be used because of interference by uranium 

lines at 2837.328 and 2837.187 A. The less sensitive 

thorium · lines at 2703. 962 and 2565. 597 A then must 

be utilized, thus reducing the visual detection limit 

of thorium from 0.1 percent to 1 percent. The maximum 

sensitivities of Al, B, Ca; Cu, Li, Mg, Si, Ti, and 

V are limited by the presence of these elements as 

residual impurjties in the regular grade carbon electrodes. The method is not designed for extreme 

sensitivity but rather for a means by which major and 

minor concentrations of 6ff elements in small samples 

may be checked in one exposure. 

Table 2 lists the wavelengths (Harrison, 1939) 

and individual sensitivities of the analytical lines 

used. Wherever practicable two or more lines are 

listed for each of the major, minor, and trace concentration ranges reported. In spectrographic 

quantitative analysis the utilization of various lines 

for different ranges of element concentrations is 

neeessary (Harrison and others, 1948); in a qualitative method the use of such lines in addition to the 

persistent lines is advisable, especially where the 

concentration of an element lies on or close to the 

boundary of demarcation between percentage brackets. 

The choice of the lines was guided by the various tables 

in the literature (Waring and Annen, 1952; Waring 

and Mela, 1952; Harrison, 1939; Brode, 1943; Harvey, 

1947), by considerations of freedom from interference 

by the lines of closely associated elements, and by 

checks of the solution standard plates with spectrograms of 1-mg samples of National Bureau of 

Standards standard samples and other standards 

5 

available.Q_y..rin<J.!Q interference by the cyanogen bands, 

a number of persistent lines cannot be used, for 

instance those of Kat 4047 and 4044 A and of In at 

4511 A. 

Table 3 lists the results of chemical micro -

analyses of some samples originally analyzed oy the 

spectrographic microqualitative method. These 

samples were available in amounts of only a few 

milligrams, and the qualitative spectrographic xesults 

sliown were intended to serve as a guide for the subsequent quantitative chemical analyses. Comparison 

of the 31 dete'rminations of 13,elements in the eight 

samples indicates seven disagreements of the spectrographic results with the chemical in the magnitude 

of one percentage brae ket. These disagreements were 

not considered too serious because it was still possible to identify the minerals from the data at hand. 

Table 4 lists a number of the mineral identifications of small single -grain samples that have been 

accomplished by agreement of the spectrographic 

microqualitative analyses with the data from the X-ray 

diffraction patterns. The spectrographic determinations of more than 40 different elements have thus 

been checked on a qualitative basis. 

The compositions of the standard solutions 

(Waring and Annen, 1952) are tabulated on pp. 14-16. 

FUTURE PROGRAM. 

Plans for further improvement of the microqualitative method include an investigation of the 

possible application of a controlled arc atmosphere 

designed to eliminate the cyanogen bands obscuring 

a large number of persistent lines. The sensitivities 

for elements such as Cs, Rb, Th, U, and many rare 

earths might thus be increased. The preparation of 

standard spectrograms on the basis of 0. 5 mg of 

sample rather than 1 mg, involving the dilution by a 

factor of two of the present standard solutions, is 

also being considered. Such spectrograms, by !representing a sample· weight closer to that usUa.lly 

used, would aid in making the method more nearly 

semiquantitative. 

LITERATURE CITED 

Brode, W. R., 1943, Chemical spectroscopy, 2d 

ed., New York, John Wiley and Sons, Inc. 

Harrison, G. R., 1939, M~ I. T. wave-length tables, 

New York, John Wiley and Sons,Inc. 

Harrison, G. R. , Lord, R. C. , and Loofbourow, J. R., 

1948, Practical spectroscopy, New York, PrenticeHall, Inc. , pp.457-458. 

Harvey, C. E., 1947, A method of semi-quantitative 

spectrographic analysis, Glendale, Calif. , Applied 

Research Laboratories. 

Jaffe, Howard, 1949, Visual arc s~ctroscopic 

detection of halogens, rare earths and other elements by use of molecular spectra: Am. 

Mineralogist, vol. 34, pp. 667-674. 

Lee, 0. I. , and Wright, T. A. , 1939, On identifying 

minerals with the aid of the spectrograph: Proc. 

6th Summer Conference on spectroscopy and its 

application, New York, John Wiley and Sons, Inc. 

_Nachtrieb, N. H., 1950, Principles and practice of 

spectrochemical: analysis, pp. 235-237, New York, 

McGraw:-Hill Book Co., Inc. 
Peterson, M. J., Kauffman, A. J., Jr., and 

Jaffe, H. W., 1947, The spectroscope in determinative mineralogy: Am.Mineralogist, vol. 32, 

pp. 322-335. 

Tongeren, W. van, 1938, Contributions to the 

knowledge of the chemical composition of the earth's 

crust in the East Indian Archipelago. I. The 

spectrographic determination of the elements 

according to arc methods in the range 3600-5000 A. 

II. On the occurrence of rarer elements in the 

Netherlands East Indies, D. B. Centen's, 

Amsterdam. 

6 

Waring, C. L., and Annell, C. S., 1951, A semiquantitative spectrographic method for the analysis 

of minerals, rocks, and ores: U. S. Geol. Survey 

Trace Elements Inves.Rept. 143. [Unpublished.] 

--~...---....,..,...- 1952, A semiquantitative spectrographic method for the analysis of minerals, rocks, 

and ores (II): U. S. Geol. Survey Trace Elements 

Inves.Rept. 215. [Unpublished.] 

Waring, C. L., and Mela, Henry, Jr., 1952, the 

determination of small amounts of rare earths in 

phosphate rocks: U. S. Geol. Survey Trace Elements 

Inves. Rept. 239. [Unpublished.] 
Table 1.--Sensitivities on the basis of 1-mg samples for the elements determined 

by the microqualitative method 

Percent Percent Percent Percent 

Ag- 0.001 Eu*O.l Mo-0.1 Sm-1.0 

Al- .001 F -1.0 Na- .1 Sn- .1 

As- .1 Fe- .1 Nd-1.0 Sr-1.0 

Au- .01 Ga- .1 Ni- .1 Ta- .1 

B - .01 Gd- .1 Os-1.0 Tb-1.0 

Ba- .1 Ge- .1 p -1.0 Te-1.0 

Be- .001 Hf- .1 Pb- .1 Th- .1 

Bi- .01 Hg-1.0 Pd- .1 Ti- .01 

Ca- .1 Ho- .1 Pr-1.0 Tl-1.0 

Cb- .1 In- .1 Pt- .01 Tm- .1 

Cd- .1 Ir-1.0.~ Rb-1.0 u -1.0 

Ce- 1.0 K - .1 Re-1.0 v - .1 

Co- 1.0 La- .1 Rh- .1 w -1.0 

Cr- .1 Li- .01 Ru-1.0 y - .01 

Cs-10.0 Lu- .1 Sb- .1 Yb- .01 

Cu- .001 Mg- .001 Sc- .1 Zn-1.0 

Dy- 1.0 Mn- .01 Si- .01 Zr- .1 

Er- .1 

• A second e~posure is required for the. fluorine determination. 

Table 2.--Wavelengths and sensitivities of the analytical lines used in the microqualitative 

method 

Wavelength Sensitivity Wavelength Sensitivity 

Element (A) (percent) Element (A) (percent) 

Ag--------------- 3280.683 0.001 Be------------- 3131.072 0.001 

3382.891 .01 3130.416 .001 

5465.487 10.0 2348.610 .001 

3321.343 ~ .1 

Al--------------- 3092-713 .001 2350.685 10.0 

3082.155 .01 

2660.393 1.0 Bi------------- 3067-716 0.01 

2652.489 1.0 2938.298 .1 

2575-100 1.0 2897-975 .1 

2567-987 1.0 3024.635 1.0 

2989.029 1.0 

As--------------- 2349.84 .1 2780.521 10.0 

2860.452 1.0 2627-906 10.0 

2780.197 1.0 

2898.71 10.0 Ca------------- 4226-728 .1 

2492.91 10.0 3179-332 .1 

3158.869 .1 

Au--------------- 2675-95 .01 8542.089 1.0 

2427-95 .1 8662.140 10.0 

3122.781 1.0 8498.018 10.0 

2748.26 1.0 

2700.89 10.0 Cd------------ 3261.057 .1 

2641.49 10.0 2980.628 1.0 

2288.018 1.0 

B---------------- 2497-733 .01 2265.017 1.0 

2496.778 .i)l 4799-918 10.0 

2981.34 10.0 

Ba--------------- 4934.086 .1 2836.907 10.0 

6141.716 1.0 

5853.679 1.0 Ce------------ 4222.599 1.0 

3071.591 10.0 3272.253 1.0 

2634.783 10.0 3056.777 10.0 

3055-243 10.0 

2651.006 10.0 

7 
Table 2.--Wavelengths and sensitivities of the analytical lines used in the microqualitative method-~Continued 

Wavelength Sensitivity Wavelength Sensitivity 

Element (A) (percent) Element (A) (percent) 

Co--------------- 3453.505 1.0 Gd------------ 3100.508 0.1 

3412.633 1.0 3034.059 1.0 

3412.339 1.0 3032.850 1.0 

3044.005 1.0 3027.612 1.0 

2521.363 1.0 2840.236 10.0 

2663.529 10.0 2809.720 10.0 

2649.940 10.0 

2519.822 10.0 Ge------------ 3039.064 .l 

2651.'?75 .l 

Cr--------------- 4289.721 .l 2651.178 .;L 

4274.803 .l 3269.494 1.0 

4254.346 .l 2691.344 1.0 

2843.252 .l 2740.431 10.0 

2835.633 .l 2589.188 10.0 

2860.934 1.0 2533.229 10.0 

2855.676 1.0 

2769.915 10.0 IIf------------ 3134.718 .l 

2731.908 10.0 3072.877 .l 

3012.90:1 .l 

Cs--------------- 8521.10 10.0 2861.696 1.0 

2861.012 1.0 

Cu--------------- 3273.962 .001 2683.353 10.0 

3247.540 .001 2531.193 10.0 

2618.366 1.0 

2492.146 1.0 Hg------------ 2536.519 1.0 

2766.371 10.0 3131.833 10.0 

2441.637 10.0 3131.546 10.0 

3125.663 10.0 

PY--------------- 3407.80 1.0 

3393.583 l.O Ho------------ 3456.00 .l 

3385.027 1.0 3453.13 1.0 

3280.10 1.0 3416.46 1.0 

3251.260 1.0 3398.98 1.0 

Er--------------- 3264.781 .l In------------ 3256~090 .l 

3230.585 .l 3039-356 .l 

2964.518 1.0 3258.564 1.0 

2753.878 10.0 

Eu--------------- 2813.95 .l 2710.265 10.0 

29o6.676 1.0 

2727·780 1.0 Ir------------ · 3220.780 1.0 

2685.65 10.0 2639.712 1.0 

2678.28 10.0 2543.971 1.0 

2534.457 10.0 F-------------~-- 6o64.4 1.0 2533.131 10.0 

( CaF ba~d heads) 6036.9 1.0 

5291.0 10.0 K------------- 7698.979 .l 

7664.907 .l 

Fe--------------- 3020.640 .. 1 

2599-396 .l La------------ 3337-488 .1. 

2739-546 1.0 3344.560 1.0 

2598.369 1.0 3303.11 1.0 

3100.304 10.0 3265.67 1.0 

3099-971 10 .. 0 2808.39 10.0 

3099.897 10.0 2610.335 10.0 

Ga--------------- 2943.637 .l Li------------ 6707.844 .01 

2944.175 1.0 6103.642 1.0 

2874.244 1.0 3232.61 1.0 

2719.653 10.0 2741.31 10.0 

2500.173 10.0 

8 
Table 2.--Wavelengths and sensitivities of the analytical lines used in the microqualitative method--Continued · 

Wavelength Sensitivity Wavelength Sensitivity 

Element (A} (percent) Element (A) (percent) 

Lu-------------- 3077.60 o.l Pb------------- 2833.069 0.1 

2615.42 .1 2802.003 .1 

2619.26 1.0 2614.178 .1 

2613.40 1.0 2873-316 1.0 

2685.08 10.0 2823.189 1.0 

2392.19 10.0 2663.166 1.0 

2393-794 10.0 

Mg-------------- 2852.129 .001 

2802.695 .001 Pd------------- 3421.24 .1 

2795-53 .001 3242.703 .1 

2782.974 1.0 3251.640 1.0 

2779.834 1.0 2763.092 1.0 

2776.690 1.0 3002.652 10.0 

2922.492 10.0 

Mn-------------- 2576.104 .01 

2605.688 .1 Pr------------- 4241.019 1.0 

2593-729 .1 4225.327 1.0 

2939-304 1.0 5322.778 10.0 

2933.o63 1.0 5259-743 10.0 

3044.567 10.0 

2584.308 10.0 Pt---... --------- 3064.712 .01 

2997-967 .1 

Mo-------------- 3193-973 .1 2659.454 .1 

3170-347 .1 2650.857 1.0 

2816.154 .1 2646.886 1.0 

3208.834 1.0 2803.239 10.0 

3158.165 1.0 2639-350 10.0 

2784.992 10.0 

2763.620 10.0 Rb------------- 7947.60 1.0 

7800.227 1.0 

Na-------------- 5895-923 .1 

5889-953 .1 Re------------- 3464.722 1.0 

3302.988 10.0 3460.47 1.0 

3302.323 10.0 2715.470 10.0 

2674.337 10.0 

Nb-------------- 3225.479 .1 

3094.183 .1 Rh------------- 3434.893 .1 

2931.469 1.0 3396.85 l.O 

2876.947 1.0 3283.573 1.0 

2875-392 1.0 3280.55 1.0 

2746.104 10.0 3271.612 10.0 

2745.729 10.0 3263.144 10.0 

Nd-------------- 4303-573 1.0 Ru------------.;.. 2874.984 1.0 

4247.367 1.0 2735-718 1.0 

3328.270 10.0 2678.758 1.0 

3275.218 10.0 2886.536 10.0 

2734.349 10.0 

Ni-------------- 3050.819 .1 

3002.491 .1 Sb------------ 2598.062 .1 

2992.595 1.0 2877.915 1.0 

2943.914 1.0 2769.939 1.0 

2907.459 10.0 2718.893 10.0 

2798.653 10.0 2670.643 10.0 

Os-------------- 3058.66 1.0 Sc------------- 2560.227 .1 

2909.061 1.0 2552.359 .1 

3301.559 10.0 2555-799 1.0 

2838.626 10.0 2545.204 1.0 

2822.131 10.0 

P--------------- 2553.28 1.0 

2535.65 1.0 

2554.93 10.0 

2534.01 10.0 

9 
Table 2.--Wavelengths and sensitivities of t~ analytical lines used in the microqualitative 

method--Continued 

Wavelength Sensitivity Wavelength Sensitivity Element (A) (percent) Element (A) (percent) -

Si-------------- 2881.578 0.01 Tm------------ 3133.89 .1 

2516.123 .01 3131.26 .1 

2987.648 l.O 4242.15 l.O 

2435.159 l.O 3462.20 l.O 

2532.378 j10.0 3362.61 l.O 

2438.782 10.0 

U------------- 4244.372 l.O 

Sm-------------- 3273.477 l.O 4241.669 l.O 

3272.803 l.O 2882.741 l.O 

3254.378 l.O 

3254.290 l.O V------------- 3185.396 .l 

3253.931 l.O 3183.982 .1 

3183.406 .1 

Sn-------------- 3034.121 .1 3202.381 1.0 

2839.989 .1 3198.012 l.O 

3009:147 l.O 3214.750 10.0 

2863.327 l.O 3212.434 10.0 

2850.618 l.O 

2661.248 10.0 W------------- 2946.981 l.O 

2571.592 10.0 2944.395 1.0 

2947.384 10.0 

Sr-------------- 4607.331 l.O 2589.167 10.0 

3464.457 l.O 

4305.447 10.0 Y------------- 3242.280 .01 

3380.711 10.0 3216.682 .01 

3200.270 .1 

Ta-------------- 2685.11 .1 3195.615 .1 

2635.929 .1 2984.256 l.O 

2714.674 l.O 2422.185 l.O 

2675.901 l.O 3o86.858 10.0 

2902.046 10.0 3055.22 10.0 

2891.843 10.0 

Yb------------ 3289.37 .01 

Tb-------------- 4278.51 l.O 2970.564 .1 

3324.40 l.O 3031.11 l.O 

3219.95 l.O 2653·75 I l.O 

3218.93 l.O 3107.897 10.0 

Te-------------- 2385.76 l.O Zn------------ 3345.020 l.O 

2383.25 1.0 3302.588 l.O 

3282.333 1.0 

Th-------------- 2837.299 .l 2800.869 1.0 

2832.319 .1 4810.534 10.0 

2870.413 1.0 2770.984 10.0 

2842.815 1.0 2770.865 10.0 

2703.962 1.0 

2565.597 1.0 Zr------------ 3438.230 .1 

4391..114 10.0 3391.975 .1 

2758.813 1.0 

Ti-------------- 3241.986 .01 2752.206 1.0 

3239.038 .01 2889.430 10 .. 0 

3236.573 .01 2888.036 10.0 

3234.516 .01 

3088.025 .01 

3078.645 .1 

3072-971 .1 

3072.107 .1 

2956.131 1.0 

2941.995 1.0" 

2619.939 10.0 

2605.151 10.0 

T1-------------- 2767.87 1.0 

5350.46 10.0 

2918.32 10.0 

10 
..... 

..... 

Table 3,.--Comparison of chemicala quantitative and spectrographicb qualitative microanalyses of samples of uranium minerals 

[Columns 1-61 (TWC 2050, TWS 712, lot 3218), columns 1·8, (TWX 319)] 

Element 

Al---------------------

Ca---------------------

Cu---------------------

Fe---------------------

Mg---------------------

Pb---------------------

Si---------------------

Th---------------------

Ti---------------------

U ---------------------

V --------------------- Er---------------------

y --------------------- Rare earths------------

Element 

Al--------------------- Ga---------------------

Cu---------------------

Fe---------------------

Mg---------------------

Pb---------------------

Si---------------------

Th---------------------

Ti---------------------

U---------------------- V----------------------

Er---------------------

Y-------------------•-- Rare earths------------

Kasolite 

Chemical I Spectro- ( percent) ~aphic 

0.71 

29.0 

4.9 

43.5 

1 

Trace 

Major 

Major 

Major 

Beta-uranotil 

Chemical! Spectro- (percent) graphic 

5 

5.2 Minor 

6.1 Major 

49.3 Major 

Uranophane 

Chemical J Spectro- (percent) graphic 

2 

7-3 Minor 

6.2 Major 

50.8 Major 

Sklodowskite 

Chemical Spectro-

(percent) graphic 

6 

--- --- 2.5 Minor 

- --- - --- 1.3 Minor 

4.9 Minor 

6.5 ~ajor 

50.3 I Major 

I 

I 

"chemical results • oxides reduced to elements. 

bMajor, approximately 10 percent or more; Minor, approximately 1-10 percent; and Trace; approximately 0.1-1 percent. 

Cuprosklodowskite 

Chemical r Spectro- (percent) graphic 

3 

5-3 Minor 

4.8 Major 

53.2 Major 

Brannerite 

Chemical Spectro-

(percent) graphic 

7 

---

2.0 I Trace 

---

1.8 I Minor 

0.23 Trace 

4.4 Minor 

19.7 Majer 

33.8 Major 

--

Minor 

Trace 

6.5 

1Belgian C011go; lab. no. 75083. ~Jachrmov, Bohemia; lab. no. 75087. 

I 

Soddyite 

Chemical I Spectro-

(percent) I araphic 

4 

4.1 Major 

68.0 Major 

Calcium ura~lvanadate 

Chemical 1 Spectro-

(percent) I graphic 

0.2 

4.5 

49.3 

12.2 

8 

Trace 

Minor 

Major 

Major 

2yllncey, N.c.; lab. no. 75084. 7Belg~an <:ongo; lab. no. 75088.. . 

3Jachymov, Bohemia; lab. no. 75085. Dean s mtne,. Mono County, Cahf.; lab. ·no. 66779; lot no. 595; (TWC 1959, TWS 569). 

4aetjilln C011go; lab. no. 75086. Ssmall Spot mtne, Mesa County, Colo.; sample no. JJK/1/52; lot no. 0-22; (TVIC 2052; TWS 786). 
1-4 

1:'1:1 

Table 4.--Mineral identifications accomplished by agreement of spectrographic microqualitative analyses with data from X-ray diffraction patterns 

Sample no. Lot no. 

EC-52------ 0-70 

EC-53------ 0-70 

EC-54·------ 0-70 

EC-56------- 0-70 

EC-59------ 0-70 

EC-64------- 0-70 

EC-65------ 0-70 

EC-76------- 0-70 

FK-26F-----~ 1193 

YC-1-51----l 

1635 

J-59------- 1128 

AIM-170---- 0-20 

T-38a------ 1128 

DN·31A----- 1708 

J-102C----- 1128 

CS-3-4-1(1)- 1629 

J-103------- 1128 

J-81-------- 1128 

J-102B------ 1128 

4493-C(3)--- 551 

2904-G(l)--- 551 

4419-H(3)-- 551 

JNS-2-------1 0-1 I 

P-59-Ba-----1 0-51 I 

Trace Elements 

X-ray film no. 

2286 

2287 

2293 

2294 

2313 

~314 

2315 

2283 

1986 

1975 

2389 

1919 

2476 

2067 

2424 

2244 

2409 

2346 

2423 

2251 

2405 

2166 

2498 

1692 

Mineral identification TWS report 

Minerals for standard X-ray patterns 

Azurite--------------------------------- 738 

Chrysocolla----------------------------- 738 Apophyllite-~--------------------------- 738 

Cerussite------------------------------- 738 

Franklinite----------------------------- 738 

Pyrargyrite----------------------------- 738 

Realgar--------------------------------- 738 

Talc------------------------------------ 738 

Uranium-bearing minerals 

Quartz and carnotite-------------------- 549 

Tyuyamunite and clay(?)----------------- 542 

Calcium uranylvanadate------------------ 770 

Rauvite--------------------------------- 533 

Rauvite and quartz---------------------- 789 

Uranophane and phosphuranylite---------- 597 

Autunite-------------------------------- 774 

Autunite-uranocircite------------------- 677 

Autunite, saleeite, and torbernite------ 774 

Zeunerite------------------------------- 770 

Torbernite------------------------------ 774 

Uraninite and smaltitecloanthite-------- 690 

Huttonite------------------------------- 761 

Brannerite, thorite, and samarskite----- 727 

Rare-earth minerals 

tAllanite--------------------------------1 778 

IBastnaesite-----------------------------1 522 

Cu --- SiAl 

Cu Si Al Mg 

Ca Si K F Al Na 

Pb --- Ca 

Zn Fe Mn Al 

Ag Sb Si Zn Cu 

As --- Ca 

Mg Si --- Fe Al -------

Si u v Mg I Na K Al 

Fe 

u v Si Ca Al Fe Mg Cu 

u v Ca Si Na Mg Al 

u v Ca Al Ti Ba 

Si 

u Si V Ca Al Na Fe 

u Si Ca Al Na Mg 

K p As 

u p Ca Si Cu Mg Fe 

Na BaAl 

u p Si Ba Na Fe Mg 

Ca Al 

u p Ca Mg Si Na Cu Al Fe 

u As CuBa Si Na 

iJ p Cu Si Fe Mg As 

Ca Na K Ba Al 

u Si As Co Cu Na Y 

Ni Fe Ba Al Mg 

Th S1 U Ca Fe Na Pb K B 

Mg Al Mn 

Th Ti u Si Nb Fe Bi Na 

y Ni Ca 

1 Si Fe I Al Ce La I Mn K 

Ca Na Mg 

Th Nd Pr 

ICe I LaY Ca J Mg Mn Pb 

Al Fe Si Th 

p 
51P-72a-----

51P-72b-----, 

4428--------1 

U.S.N.M. 2 no. 80183 

J-102A------

w-88--------

AT-20-------

4099--------

JNS-1-------

J-56--------

Anl-173----- ~ 4477~A------

51-AWe-107--

51-P-67-----

51-P-67m----

J-102D------

.Anl-186-----

4385--------

K-35-3------

WE-186A-----

1613 

1613 

3036 

0-70 

1128 

1128 

1126 

3035 

0-1 

1128 

0-20 

551 

3035 

1613 

1613 

1128 

0-20 

3036 

1637 

3035 

2266 

2272 

2192 

B-255 aRd 

B-256 

2426 

2477 

2367 

2043 

2479 

2377 

1922 

2148 

2023 

2246 

2241 

2393 

1913 

2193 

2486 

2196 

Florencite-----------------------------

Florencite and rutile------------------

Parisite-------------------------------

Cyrtolite------------------------------

Miscellaneous minerals 

Quartz and hydromica-------------------

Kaolinite------------------------------

Gibbsite-------------------------------

Topaz and impurities-------------------

Biotite--------------------------------

Apatite and hydromica------------------

Hewettite------------------------------

Melanovanadite, quartz,and barite(?)---

Vosenite-------------------------------

Hematite, rutile, and ilmenite---------

Magnetite------------------------------

Goethite-------------------------------

Conichalcite and quartz----------------

Orpiment-------------------------------

Sphalerite-----------------------------

Pyrochlore-microlite-------------------

1Major, appro:dmately 10 percent or more; Minor, approximately 1-10 percent; and Trace, approximately 0.1-1 percent. 

2u. S. National Museum sample no. 

3u. S. National Museum X-ray film no. 

687 

687 

658 

746 

774 

789 

757 

576 

and 

579. 

778 

770 

533 

723 

571 

687 

687 

770 

561 

655 

787 

654 

P Al Ce 

P Ti 

Ce La 

Zr Si Hf 

Si 

SiAl 

SiAl 

Al Si 

Si Fe 

Ca Si 

v 

v 

Fe Mg B 

Fe Ti 

Fe 

Fe 

Cu Ca 

As Si 

As 

Zn Si 

Ca Ta 

Si Th La 

Fe Ca Zr 

Si Ce Al 

Zr La 

Ca Nd 

Y Fe Ca 

K Fe Al 

Mg Na 

K Mg Na 

Na 

F Pb 

Al Mg K 

Ca Na 

Fe Mg K 

P Al Na 

Ca 

Ca Si Ba 

Mn Si 

Si Mn 

Si Na 

Si Na 

v 

Mg Na 

Nb Na 

Ti Gd Pb 

Y Ba K 

Th Pb Fe 

K BaY 

Ca 

Fe 

U Mn Th 

Na Al Yb 

Gd.B 

Ca Ti 

Ca Fe Ti 

Mg Ca K 

Cu Fe Ni 

CaFe 

Li Ti 

Mn V Ti 

Ba 

Ti Ba Si 

Fe Mg Na 

Ti Al 

Ca Na Ti Ni 

Na Mg Al Ca 

Ti Mg Al Mn 

Ca 

Cu Ca Al K 

Mg 

Al Mg Mn Ba 

Al Mn Si Ti V 

K 

Fe Mn Si Ti 
COMPOSITION OF STANDARD SOLUTIONS 

(Waring and Annell, 1952) 

The following standard solutions were made from compounds and elements available in the laboratory. The 

compounds were dissolved in distilled water unless otherwise noted. 

Element 

standardized 

Ag 

Al 

As 

Au 

B 

Ba 

Be 

Bi 

Ca 

Cd 

Ce 

Co 

Cr 

Cs 

Cu 

Dy 

Er 

Eu 

F 

Fe 

Ga 

Ge 

Gd 

Hf 

Hg 

Ho 

In 

Compound 

used 

AgN03 , reagent-------------

Solution 

A1Cla.6Hz0, C. P. --------- Compound dried in oven at 140 C and dissolved in cold acidified 

HzO. 

As 2 0 3 , Nat. Bur. Standards 1;1 HN0 3 , heated. Diluted to volume with HzO. 

no. 83a. 

Au, metal------------------ Aqua regia. Boiled down several times with HCl (cone) to drive 

off HN0 3 • Diluted to volume with H20. 

HaBOa, C. P. --------------

BaClz. 2Hz0, C. P. ---------

Be, metal------------------ Dilute HC 1. 

Bi, metal------------------- 1:1 HN0 3 , diluted to voiume with H20. 

CaClz. 2H20, anal. reagent--

CdClz. 2!H2 0, C. P. --------

CeOz-·---------------------- H2S04, (cone) heated to form amber, Ce(S04)z. 6 percent H2S0 3 

added to form colorless Ce 2 (S0 4)a. Diluted to volume with H2 0. 

Cr, metal ---------- ------- 1:1 H2S04. 

CsCl, C. P. ----------------

CuO, reagent--------------- Dilute HCl. 

DyzOa --------------------- 1:1 HCl. Diluted to volume with H20. 

ErzOa --------------------- 1:1 HCl. Diluted to volume with H20. 

EuzOa--------------------.!- 1:1 HCl, heated. Diluted to volume with H20. 

CaClz, C. P. and NaF, H20 (2 solutions). 

C. P. 

Fe, metal------------------ Dilute H2S04. 

Ga, metal, C. P. ----------- Aqua regia. Diluted to volume with H20. 

GeOz, C. P. --------------- HF, 48 percent. H2S04 (cone), added and heated to drive off HF. 

Diluted to volume with H20. 

GdzOa --------------------- Dilute HCl. 

HfOz----------------------- Dilute H2S04 , heated and H20 2 , 3 percent, added until dissolved. 

Diluted to volume with H20. 

HgC1 2 , reagent-------------

HozOa --------------------- 1:1 HCl, heated. Diluted to volume with H20. 

In, metal------------------- HNOa, cone. Diluted to volume with H20. 

14 
Element 

standardized 

Ir 

K 

La 

Li 

Lu 

Mg 

Mn 

Mo 

Na 

Nb 

Nd 

Ni 

Os 

p 

Pb 

Pd 

Pr 

Pt 

Rb 

Re 

Rh 

Ru 

Sb 

Sc 

Si 

Sm 

Sn 

Sr 

Ta 

Tb 

Te 

Compound 

used Solution 

Ir metal powder, C. P. ------ Fused with 3 parts KOH and 1 part KN03 • Fusion dissolved in 

aqua regia. Si0 2 filtered off. Filtrate boiled down to small 

volume. Crystals of K2 IrCls separate upon cooling and dissolve 

in H 20. 

HKCeH404, Nat. Bur. 

Standards. 

La 20s --------------------- Dilute HCl. 

LizCOs, reagent------------ Dilute HCl. 

Lu 20s---------------------- 1:1 HCl, heated. Diluted to volume with H20. 

Mg, metal------------------ Dilute HCl. 

MnClz. 4Hz0, C. P. ---------

Mo, metal------------------ Aqua regia, heated. Diluted to volume with H20. 

NaCl, reagent--------------

Nb, metal------------------ 48 percent HF. Diluted to volume with HN03 , cone. 

NdzOs---------------------- 1:1 HCl. Diluted to volume with H20. 

Ni, metal------------------- 1:1 HN0 3 , heated. Diluted to volume with H20. 

Os metal powder, C. P. ------ Os metal powder heated with aqua regia in flask fitted with reflux 

condenser. 

NaH2PO-t. HzO, C. P. --------

Pb(NOs)z, C. P. ------------

Pd, wire-------------------- Aqua regia. Diluted to volume with H20. 

PrsOu ~-------------------- 1:1 HCl. Diluted to volume with H20. 

Pt, sheet------------------- Aqua regia. Boiled down several times with HCl, (cone) to drive 

off HN03 • Diluted to volume with H2 0. 

RbCl-----------------------

Re, metal------------------- HN0 3 , cone. Diluted to volume with H20. 

RhCla, dry, C. P. ---------- Dilute HCl. 

(NH4)zRuCl5---------------- Hot H20. 

Sbla, C. P. ----------------- Acetone+ HCl, dil. 

Scz(S04)a. 5Hz0 -------------

Si0 2 , pure------------------ Na 2C0 3 fusion. Diluted to volume with H20. 

SmzOa-------..:_____________ Dilute HCl. 

SnClz. 2Hz0, reagent--------

SrC0 3 , reagent-------------- Dilute HCl. 

Ta, metal------------------- 48 percent HF + HN03 , cone. Diluted to volume with HzO. 

Tb407---------------------- 1:1 HCl, heated. Diluted to volume with H20. 

HzTe04. 2Ha0, C. P. -------- 1:6 HNOs, heated. 

15 
Element 

standardized 

Th 

Ti 

Tm 

Tl 

u 

v 

w 

y 

Yb 

Zn 

Zr 

Compound 

used 

Th(NOa)<~. 4H20, C. P. -------

Solution 

Ti02, C. P. ---------------- 48 percent HF + H20 2. H2S04, (cone), added and heated to drive 

off HF. Diluted to volume with H20. 

Tm20a--------------------- 1:1 HCl, heated. Diluted to volume with H20. 

TlN03 , C. P. --------------

(U02)(C 2Ha02h· 2H20 

C. P. 

NH4VOa, C. P. ------------- 1:1 HCl. Diluted to volume with H20. 

W, metal------------------- 48 percent HF + HN0 3 , (cone), heat. Diluted to volume with H20. 

Y 20a----------------------- 1:1 HCl and heat. Diluted to volume with H20. 

Yb 20a----------,----------- 1:1 HCl, heated. Diluted to volume with H20. 

ZnO, reagent--------------- Dilute HCl. 

16 

GPO 11·•11'1'1