Collection, Preparation 

and Testing of NIST 

Hard Rock Mine Waste 

Reference Material SRM 2780

by S.A. Wilson1 , P.H. Briggs 1 , Z.A. Brown1 , 

J.E. Taggart 1 and R. Knight 1

Open File Report 99-370

1999

This report is preliminary and has not been reviewed for conformity 

with U.S. Geological Survey editorial standards. Any use of trade 

names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government

U.S. DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

1 Denver, Colorado
Table of Contents

Introduction .......................................... 1

Sample Collection and preparation...................... 3

Results and Discussion ................................ 4

Conclusions

Bibliography........................................... 7

Table 1 

Table 2

Table 3

TABLES 

USGS analytical procedures 8

Summary results for USGS and contract 

lab analysis of NIST Mine Waste 

reference material SRM 2780 ............ 9

USGS summary results for the 

analysis of SRM 2710 ...... 10

APPENDICES 

Appendix A USGS WD-XRF results for NIST SRM 2780 .... 11

Appendix B USGS ICP-AES results for NIST SRM 2780 ... 12 

Appendix C USGS INAA results for NIST SRM 2780 ...... 13

Appendix D USGS single element results for NIST

SRM 2780 ................................ 14

Appendix E USGS contract lab single element results

for NIST SRM 2780 ....................... 15
Introduction

In the western United States there are an estimated five 

hundred thousand abandoned mines located on public and private 

lands. These sites commonly contain significant quantities of mine 

waste material which was discarded without environmental concern 

during historic mining operations. Typically this waste is 

responsible for the generation of acidic (pH 2-4) drainage, 

containing elevated concentrations of heavy metals. This toxic 

combination contaminates adjacent waterways leaving them void of 

biological activity for several kilometers downstream. Remediating 

historic mine sites often requires millions of public and private 

dollars and thousands of man hours to return the site to its 

premining condition.

Accurately evaluating the environmental impact of mine waste 

is hampered by the variability in laboratory methodology used to 

assess its hazardous nature. This problem is compounded by the 

difficulty encountered in comparing data from different labs even 

though they use the same techniques. These problems have developed 

in part due to the lack of appropriate geochemical reference 

materials (GRMs) which mimic mine waste composition. In response 

to this need, the United States Geological Survey (USGS), the 

National Institute for Standards and Technology (NIST) and the 

United States Environmental Protection Agency (U.S. EPA) cooperated 

in the development of a reference material dedicated to the study 

of hard rock mine waste. The goal was to produce a GRM which could 

be used in the development of appropriate analytical procedures, 

assist in intra-laboratory data evaluation, and help create 

reliable quality assurance programs for the industry. Due to the 

complex nature of mine waste drainage, the project was designed to 

examine both the total element composition and water extractable 

constituents of the proposed GRM. Determining the total element 

composition of this material was the responsibility of NIST and the 

USGS. Quantifying water extractable constituents was coordinated 

through the Acid Drainage Technology Initiative (ADTI) group. ADTI 

is a working group of scientists from the public and private 

sectors dedicated to a better geochemical understanding of coal and 

hard rock mine waste in the United States.

The USGS was charged with identifying a collection site, as 

well as collecting and physically preparing two "identical" lots of 

material. The area selected for sample collection was the 

Silverton mining district, located in San Juan county (392 mi2 ) , 

Colorado. The district, located near the town of Silverton, 

Colorado, sits at the southwestern end of the Colorado mineral belt 

(Cunningham et al., 1995; Ransome, F.L., 1901). The area was 

extensively mined in the late 1800's to mid 1900's, with limited 

mining occurring as late as the 1980's. At the height of its
mining activity the district officially employed up to 500 people 

at 31 mines and mills. State production records indicate that 

between 1873 and 1980, 1.4 billion pounds of lead, copper, and zinc 

were produced, as well as 51 million ounces of gold and silver 

(Colorado Bureau of Mines, 1873-1980). The estimated net worth of 

this activity is placed at 270 billion dollars.

Evidence of this intensive mining activity is still apparent 

today, in the several abandoned mills located along the Animas 

River and in the thousands of abandoned mine sites located 

throughout the valley. Abandoned mine sites are normally 

characterized by extensive piles of crushed rock adjacent to the 

mine entrance. These piles range in color from pale yellow to dark 

red, and typically contain significant quantities of pyrite, 

galena, arsenopyrite, chalcopyrite, sphalerite and other sulfide 

minerals. These metal sulfides undergo gradual oxidation producing 

significant quantities of sulfuric acid. An example of this 

oxidation process is presented in equations 1-4 for the mineral 

pyrite (FeS2 ) .

1. FeS2 + 3.502 + H2 0 ^ Fe2+ + 2H+ + 2SO4 2 "

2. 2Fe2+ + 0.502 + 2H+ ** 2Fe3+ + H2 O

3. Fe3+ + 3H2 0 ^ Fe(OH) 3 + 3H+

4. FeS2 + 14Fe3+ + 8H2 O ^ 15Fe2+ + 2SO4 2 " + 16H+

The acid generated during pyrite oxidation leaches the 

surrounding waste material of metals which are then deposited on 

the surface of adjacent particles as water soluble salts. During 

high water flow periods such as the spring runoff and summer 

thundershowers these acidic salts are mobilized from the waste 

pile, eventually draining into local streams. The combination of 

elevated metal concentrations and high acidity makes it difficult 

for indigenous animal species to survive in affected waterways. 

Extensive federal and private reclamation projects are currently 

underway in the Silverton area to remediate several of the most 

important mine waste locations.

The site selected for sample collection was located next to 

the Mayday mine, which is situated on the northeastern side of the 

Silverton caldera field, at latitude 37° 50' 52" and longitude 107° 

40' 45". The mine sits atop intra-ash flows of andesitic lava, 

primarily of the tertiary age (Ransome, F.L., 1901; Tweto, O., 

1979). Mines located along this side of the Silverton caldera 

field produced significant quantities of lead, copper and zinc as 

well as important amounts of tungsten (hubnerite).
Sample Collection and Preparation

The Mayday mine site is located on Bureau of Land Management 

(BLM) land and covers a total area of approximately 1 acre. The 

waste pile is adjacent to the mine opening and is arranged in a 

poorly defined two-bench structure. The mine dump is generally 

devoid of vegetation, despite the fact that the mine site is 

situated in a lush evergreen forest. Measuring from the adjacent 

county road, the waste pile is approximately 100 meters high, 200 

meters in width, with a sixty degree angle of repose. The mine 

waste surface material has a gray to pale yellow appearance, with 

isolated streaks of dark red, brown, or white material. The dump's 

surface material is stable to foot traffic, and is composed of 

crushed rock ranging in size from 0.5 to 5 cm in length. Large 

clods of agglomerated waste material are evident, but are easily 

disaggregated to particles 1 cm or less in diameter. Erosional 

effects on the pile are apparent, but areas of deep erosional 

scaring are limited.

The upper bench of the waste pile was selected for sample 

collection. It was divided into fifteen sections approximately 10 

m in width and 30 m in length (top to the bottom of bench) . Sample 

collection was performed by rapelling down the center of each 

section in 3 meter increments, and then collecting material within 

five meters of the rope. Samples were obtained from the top 20 cm 

of surface material, using a common garden spade. The sample was 

transferred to five gallon plastic buckets lined with a 

polyethylene bag. Using this procedure approximately 30 kg of 

material was collected from each section resulting in a total 

collected sample weight of over 450 kg.

Upon arrival at the USGS, material from each bucket was 

transferred to six plastic lined cardboard trays, and dried in a 

forced air oven (room temperature) for 24 hours. After drying 

material was mixed for 20 minutes in a 3 ft3 V-blender, and then 

transferred back into its original container. A sub-sample from 

each bucket was obtained using a plastic sample thief (30 cm x 2 

cm) and then analyzed for its total element content by the USGS. 

The contents of selected buckets were eventually combined into one 

batch and blended for 1 hour using a 10 ft3 cross flow V-blender. 

After blending, the sample was transferred back into five gallon 

containers.

As part of the cooperative arrangement between NIST, USGS, and 

ADTI, the blended mine waste material was to be divided in two 

equal size lots. The sample splitting was accomplished using a USGS
designed spinning riffler. In this procedure, material from each 

five gallon container was transferred to a specially designed 

funnel apparatus which allowed material to flow onto a rotating 

table (2 m diameter) spinning at approximately six rpms. On the 

table were positioned a set of 12 stainless steel sample splitters 

which transferred the material into a set (12) of 5 gallon plastic 

buckets. After splitting was complete, the odd and even numbered 

containers were set aside for ADTI and NIST studies respectively. 

Material for NIST was ground to pass 200 mesh (67/z) and then 

blended in a 10 ft3 cube blender for 24 hours. The ground material 

was transferred to 5 kg polyethylene bags, boxed, and radiation 

sterilized at COBE Laboratories, Lakewood, Colorado. The radiation 

dosage during sterilization ranged between 1.5 and 3.2 Mrad.

In the final preparation step, the ground/sterilized material 

was reblended and then split using the spinning riffler to produce 

~4 kg aliquots. The spinning riffler was refitted with a 72 

position sample ring, and each 4 kg aliquot was used to fill 

containers(55-60g) with material. A total of 2200 units were 

prepared in this manner.

Results and Discussion

Prior to shipping the bottled material to NIST, the USGS 

analyzed samples for major and trace elements to determine 

between-bottle homogeneity. Analytical methods used included 

Wavelength Dispersive X-ray Fluorescence (WD-XRF), Inductively 

Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), Instrumental 

Neutron Activation Analysis (INAA), Hydride Generation Atomic 

Absorption Spectroscopy (HYG-AAS), Cold Vapor Atomic Absorption 

Spectroscopy (CV-AAS), Combustion Infrared detection (C-ID), 

Coulometric Titration (CT), Fire Assay (FA), Graphite Furnace 

Atomic Absorption Spectroscopy (GF-AAS),and Potentiometric 

Titration (PT). Analyses were performed at the USGS laboratory 

facilities, Lakewood, Colorado and at the USGS contract lab in 

Ottawa, Canada. Contract lab results are designed to provide 

information on those elements not analyzed at the USGS. Samples 

used in the USGS homogeneity test represented every 100th bottle 

(22), as well as six samples selected at random. A sample of NIST 

SRM 2710 was included in the sample set for quality control 

purposes. All samples were analyzed on an as received basis. A 

brief description of USGS techniques used and their acceptable 

average element variation is presented in Table 1. More detailed 

information on USGS analytical procedures is available (Arbogast 

1996) . Homogeneity testing performed at the USGS contract lab used 

six samples selected at random. Analytical procedures used at the 

USGS contract lab are similar to USGS procedures with only minor 

modifications.
Results from the between-bottle analysis of SRM 2780 are 

presented in appendices A through E and summarized in table 2 for 

both the USGS and contract lab. Results are presented by individual 

techniques except for CV-AAS, HY-AAS, and C-ID which are grouped 

under the general heading LATA. In this study the estimate of 

total analytical uncertainty is represented by the percent 

relative standard deviation (%RSD) as determined using equation 5.

5. %RSD = element standard deviation! x 100

average element cone.

The %RSD represents a combination of two error components. The 

first reflects the between-bottle variation in element 

concentration (Vconc) and the second reflects the error associated 

with the actual analytical measurement (Em) . The USGS value of Em 

for any technique is estimated through the USGS method validation 

process, which relies on the analysis of selected geochemical 

reference materials over three nonconsecutive days. Table 1 

presents information on the average %RSD for each USGS technique 

used.

For the majority of elements quantified in SRM 2780, the 

observed %RSD is equal to or less than the technique Em. Under 

USGS guidelines, the material is considered homogeneous for that 

element within the limits established by the method. Selected 

elements display %RSD in excess of the Em values and should be 

carefully evaluated before they are considered homogeneously 

distributed. These elements include Na, P (WDXRF), Au, Ni, W 

(INAA), Hg (CV-AAS), and Co(ICP-AES).

Examination of results in table 2 reveal that several elements 

are present at elevated concentrations. In the case of Ag, As, Cd, 

Pb, Sb, and Zn, element concentrations are at least two orders of 

magnitude greater than average crustal material(Fortescue, J., 

1992; Schacklette, H. and Boerngen, J., 1984). Concentrations of 

other elements such as Cu, S, and W, are 2 to 10 times greater than 

average abundances. USGS X-ray diffraction studies indicate that 

the major mineral phases in the sample include, quartz, muscovite, 

feldspar, chlorite, a series of jarosite minerals as well as a 

significant fraction of amorphous alumino silicates. Also present 

are minor amounts of galena, sphalerite, and pyrite.

An evaluation of analytical accuracy was performed by 

comparing USGS results for the analysis of SRM 2710 with NIST 

certificate values (table 3). NIST SRM 2710 was selected as a QC 

sample because its element concentrations and mineralized 

composition are similar to SRM 2780. Prior to sample analysis a 

confidence interval was established for each element based on
certificate information and USGS quality control guidelines. In 

the case of NIST certified elements, the acceptable element 

concentration range (AECR) was established as the certified value 

± twice the NIST 95% confidence interval. Elements with NIST 

information values were assigned an AECR equal to the recommended 

value ± 20% of the mean value. Element concentrations in table 3 

that fall outside their calculated AECR are contained within 

parentheses. All values were corrected for their percent moisture 

values (1.6%), which was previously determined by the USGS.

Examination of major element results in table 3 reveal that 

the majority (82%) of major elements concentrations fall within 

their designated AECR. Exceptions are noted for Na, Si (WDXRF), Ti 

(ICP-AES) , and Ca (INAA) . The bias observed for Na and Si using 

WDXRF reflects a consistent trend in USGS analysis of this SRM 

(Wilson et al., 1994). Comparison of USGS results with NIST 

certificate values for minor and trace elements show that 88% of 

elements have observed concentrations within their calculated AECR. 

Exceptions to this trend include Co, Cr, Ga,(ICP-AES), and Ag, 

Cr, Ni, Zn, (INAA).

Conclusion

The NIST hard rock mine waste reference material SRM 2780 was 

evaluated for element homogeneity by the USGS using a variety of 

analytical procedures. Results indicate that for the majority of 

elements tested the total element concentrations show no 

significant between-bottles variation. Concentrations of selected 

metals are several orders of magnitude above normal crustal 

abundances and major mineralogical phases are consistent with the 

mineralized nature of the area.
Bibliography

Arbogast, B.F., 1996, Analytical Methods Manual for the Mineral 

Resources Surveys Program, U.S. Geological Survey, Open File report 

96-525, p 248

Colorado Bureau of Mines, 1898-1985, A Summary of Mineral Industry 

Activities in Colorado, State of Colorado, p 100.

Cunningham, C.G., Naeser, C.W., Marvin, R.F., Luedke, R.G., 

Wallace, A.R., 1994, Ages of Selected Intrusive Rocks and 

Associated Ore Deposits in the Colorado Mineral Belt, U.S. 

Geological Survey Bulletin, 2109, 26 p.

Fortescue, J., 1992, Landscape geochemistry: retrospect and 

prospect 1990: Applied Geochemistry, v 7, p. 1-53.

Ransome, F.L., 1901, A Report on the Economic Geology of the 

Silverton Quadrangle, Colorado, U.S. Geological Survey Bulletin, 

p262.

Schacklette, H.T., and Boerngen, J. , 1984, Element concentrations 

in soils and other surficial materials of the conterminous United 

States, U.S. Geological Survey Professional Paper 1270, p 105.

Tweto, O., 1979, Geologic Map of Colorado 1:500,000, U.S. 

Geological Survey Map GSG-6-2.
Table 1. USGS analytical procedures

Decomposition Sample wt Precision 

Method Procedure____g____%RSD

ICP-AES multiacid 0.200 5-10

WD-XRF Lithium 0.800 1 - 2 

Tetaborate 

Fusion

INAA none 0.7 1-10

CV-AAS Bichromate/ 0.25 2-5 

nitric acid

HYG-AAS multiacid 0.25 5-10

C-ID High temp. 0.25 5-10 

combustion
Table 2. Summary results for USGS and contract lab analysis of NIST SRM 2780

Element

Al%

Ctot

Cinorg

Corg

Ca

Fe

FeO

K

Mg

Na

P

Stot

Si

Ti

Agppm

As

Au

Ba

Cd

Ce

Co

Cr

Cs

Cu

Ga

Hf

Hg

Ho

La

Li

Mn

Mo

Nb

Nd

Ni

Pb

Rb

Sb

Sc

Se

Sr

Tb

Te

Th

TI

Tm

U

V

W

Zn

Zr

USGS 

WDXRF 

AVG STDS %RSD

8.79 0.03 0.30

0.20 0.004 2.1

2.73 0.02 0.6

3.43 0.03 0.74

0.54 0.01 1.2

(0.32) 0.01 3.1

(0.062) 0.003 5.3

34.0 0.06 0.2

0.698 0.004 0.6

(450) 30 7.2

USGS 

ICP-AES

AVG STDS %RSD

8.50 0.23 2.7

0.19 0.01 4.5

2.7 0.02 0.8

3.2 0.09 2.9

0.51 0.01 1.0

0.21 0.01 3.3

0.04 0.00 6.9

0.64 0.04 6.3

27 1 2.6

72 6 7.9

<8

900 40 4.5

12 1 4.1

61 5 7.9

(2.1) 0.5 24

48 2 3.7

220 11 5.2

26.0 0.5 1.8

<4

38 3 9.0

18 0.2 1.1

450 10 2.3

(13) 2.6 20

18 1 5.3

26 2 7.4

12 0.5 4.0

5700 110 1.9

23 2 7.5

220 6 2.7

(8) 2 32

<100

260 5 2.0

2800 130 4.7

USGS 

INAA 

AVG STDS %RSD

0.29 0.01 3.4

2.77 0.03 1.2

4.08 0.17 4.1

0.22 0.002 0.81

22.6 0.6 2.7

48.2 0.8 1.7

(0.184) 26 14

964 17 1.8

12.0 1.0 8.5

67.1 0.9 1.3

2.21 0.04 1.8

40.6 1.4 3.5

13.1 0.1 1.0

4.41 0.07 1.5

0.84 0.03 3.9

37.6 0.4 0.9

10.6 0.9 8.9

30.5 0.6 2.1

(19.5) 3.2 16

173 2 1.2

159 2 1.3

23.7 0.3 1.1

3.4 0.2 5.2

294 6 2.1

0.58 0.01 1.8

11.5 0.1 1.3

0.40 0.02 3.9

3.95 0.08 2.0

(20) 3 16

2380 53 2.2

162 16 9.9

USGS 

LATA

AVG STDS %RSD

0.17 0.01 6.0

1.23 0.02 1.2

44 3 7.8

(0.73) 0.10 14

5.15 0.13 2.5

Contract lab

AVG STDS %RSD

0.17 0.02 12

0.010 0.004 10

0.16 0.02 12

0.68 0.04 6

1.29 0.03 2

0.20 0.04 18

0.7 0.1 14

125 10 8

4.4 0.4 9

5.3 0.7 13

9.5 0.5 6

4.9 0.4 7

23.8 2.1 9

Element concentration in paraentheses have observed %RSD in excess of method %RSD
Table 3. USGS summary results for the analysis of NIST SRM 2710'

Element

Al%

Ctot

Ca

Fe

K

Mg

Na

P

Stot

Si

Ti

Ag ppm

As

Au

Ba

Cd

Ce

Co

Cr

Cs

Cu

Ga

Hf

Hg

Ho

La

Li

Mn

Mo

Nb

Nd

Ni

Pb

Rb

Sb

Sc

Se

Sr

Tb

Th

Tm

U

V

W

Zn

Zr

WDXRF ICP-AES

6.45 6.50

1.26 1.22

3.31 3.35

2.07 2.03

0.86 0.86

(1.32) 1.12

0.12 0.11

(28.31)

0.27 0.13

36

650

<8

691

21

58

(13)

(30)

3048

(16)

35.6

37.6

9956.80 9550

20.3

16.3

21.3

16

5588

10

345

77

6909

INAA LATA

2.99

(1-82)

3.47

2.08

1.11

0.02

(28)

668 599

0.49

740 .

21

57.3

9.11

(30.3)

109

3.58

30

0.89

30.7

24.2

25.9

(10.1)

129

36

9.1

0.28 0.55

358

0.68

13

0.37

27

91

(6532)

111

value

6.44

3

1.25

3.38

2.11

0.853

1.14

0.106

28.97

0.283

35.3

626

0.6

707

21.8

57

10

39

2950

34

3.2

32.6

0.6

34

10100

19

23

14.3

5532

120

38.4

8.7

330

13

25

76.6

93

6952

+/-

0.08

0.03

0.1

0.11

0.042

0.06

0.015

0.18

0.01

1.5

38

51

0.2

130

1.8

400

1

80

3

2.3

91

limit

6.6

3.6

1.31

3.58

2.33

0.937

1.26

0.136

29.33

0.303

38.3

702

0.7

809

22.2

68

12

47

3210

41

3.8

36.2

0.7

41

10900

23

28

16.3

5692

144

44.4

10.4

396

16

30

81.2

112

7134

limit

6.28

2.4

1.19

3.18

1.89

0.769

1.02

0.076

28.61

0.263

32.3

550

0.5

605

21.4

46

8

31

2690

27

2.6

29

0.5

27

9300

15

18

12.3

5372

96

32.4

7.0

264

10

20

72

74

6770

* values corrected for percent moisture

concentrations in parentheses are outside AECR for SRM 2710

10
Appendix A. 

Lab No

F-027742

F-027741

F-027740

F-027739

F-027738

F-027737

F-027736

F-027735

F-027734

F-027733

F-027732

F-027731

F-027730

F-027729

F-027728

F-027727

F-027726

F-027725

F-027724

F-027723

F-027722

F-027721

F-027720

F-027719

WD-XRF results for NIST SRM 2780 

Al% Ca% Fe, % K%

8.84

8.79

8.79

8.79

8.84

8.79

8.79

8.79

8.79

8.79

8.79

8.79

8.79

8.79

8.73

8.79

8.79

8.73

8.79

8.84

8.79

8.79

8.84

8.79

0.21

0.20

0.21

0.21

0.20

0.20

0.20

0.20

0.21

0.21

0.21

0.21

0.21

0.21

0.20

0.20

0.20

0.21

0.20

0.20

0.21

0.20

0.21

0.20

2.72

2.74

2.72

2.72

2.75

2.73

2.76

2.73

2.74

2.71

2.73

2.72

2.73

2.72

2.69

2.71

2.72

2.75

2.71

2.72

2.73

2.71

2.73

2.75

3.41

3.40

3.42

3.42

3.45

3.45

3.45

3.45

3.46

3.45

3.46

3.40

3.39

3.40

3.39

3.40

3.42

3.41

3.45

3.45

3.44

3.45

3.45

3.45

0.54

0.54

0.54

0.54

0.54

0.53

0.54

0.54

0.55

0.54

0.54

0.53

0.54

0.55

0.53

0.52

0.54

0.54

0.52

0.54

0.54

0.53

0.54

0.53

Mg%

0.05

0.05

0.05

0.05

0.05

0.05

0.05

0.04

0.05

0.05

0.04

0.05

0.05

0.05

0.05

0.05

0.04

0.05

0.05

0.04

0.05

0.04

0.05

0.05

Mn%

0.31

0.34

0.32

0.33

0.33

0.32

0.33

0.33

0.33

0.32

0.32

0.33

0.32

0.31

0.31

0.33

0.33

0.33

0.33

0.33

0.31

0.34

0.31

0.31

Na%

0.065

0.065

0.065

0.057

0.065

0.057

0.065

0.065

0.065

0.061

0.070

0.061

0.061

0.061

0.061

0.061

0.057

0.061

0.061

0.065

0.065

0.061

0.061

0.061

P%

30.0

30.0

30.0

30.0

30.1

30.0

30.0

30.0

30.1

30.0

30.1

30.1

30.0

30.0

29.9

30.0

30.0

30.0

30.0

30.0

29.9

30.0

30.0

30.0

Si%

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

T

11
Lab No

F-027742

F-027741

F-027740

F-027739

F-027738

F-027737

F-027736

F-027735

F-027734

F-027733

F-027732

F-027731

F-027730

F-027729

F-027728

F-027727

F-027726

F-027725

F-027724

F-027723

F-027722

F-027721

F-027720

F-027719

Lab No

F-027742

F-027741

F-027740

F-027739

F-027738

F-027737

F-027736

F-027735

F-027734

F-027733

F-027732

F-027731

F-027730

F-027729

F-027728

F-027727

F-027726

F-027725

F-027724

F-027723

F-027722

F-027721

F-027720

F-027719

8.5

8.8

8.6

8.5

8.0

8.4

8.6

8.4

8.3

8.3

8.1

8.4

8.5

8.4

8.3

8.9

8.9

8.8

8.5

8.7

8.6

8.7

8.5

8.4

Al%

Cu ppm

210

210

210

220

220

200

220

210

230

210

210

230

220

220

230

240

220

200

220

210

230

220

240

200

0.18

0.19

0.18

0.18

0.18

0.19

0.19

0.18

0.18

0.17

0.17

0.18

0.19

0.17

0.19

0.19

0.19

0.19

0.20

0.19

0.20

0.19

0.19

0.19

Ca%

Ga ppm

26

26

26

26

26

26

26

26

27

26

26

26

27

26

26

26

25

26

26

27

26

25

26

26

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.7

2.6

2.7

Fe%

Ho ppm

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

<4

K %

3.3

3.3

3.3

3.3

3.0

3.1

3.2

3.2

3.3

3.2

3.2

3.2

3.3

3.2

3.0

3.3

3.3

3.3

3.2

3.2

3.2

3.3

3.2

3.1

La ppm

42

42

39

42

41

41

40

39

 

36

38

36

35

36

37

35

36

32

34

33

36

36

31

42

41

0.50

0.51

0.51

0.51

0.51

0.51

0.52

0.51

0.51

0.50

0.51

0.51

0.52

0.51

0.51

0.52

0.51

0.51

0.52

0.52

0.51

0.51

0.51

0.51

Mg%

Li 

18

18

18

18

18

18

18

18

18

18

18

18

18

18

19

18

18

18

18

18

18

18

18

18

ppm

0.21

0.22

0.21

0.21

0.19

0.20

0.21

0.21

0.21

0.21

0.20

0.21

0.21

0.21

0.20

0.22

0.21

0.21

0.20

0.21

0.20

0.21

0.20

0.20

Na%

Mn ppm

460

460

450

450

440

460

450

450

480

450

460

450

460

440

450

450

440

440

460

440

470

450

440

440

P %

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.05

0.04

0.05

0.04

0.04

0.04

0.04

Mo ppm

13

14

12

12

13

12

12

12

12

22

14

12

12

12

12

12

12

12

12

12

20

12

12

12

Ti%

0.68

0.62

0.62

0.67

0.67

0.63

0.56

0.65

0.71

0.68

0.69

0.60

0.60

0.62

0.68

0.60

0.60

0.65

0.68

0.69

0.69

0.63

0.60

0.61

Nb ppm

19

18

18

18

17

18

17

18

17

17

19

17

18

18

19

20

18

18

18

18

21

18

19

18

Agppm

26

27

27

27

26

27

28

27

27

26

26

26

26

28

27

27

26

26

27

28

26

26

27

27

Nd ppm

26

26

26

25

26

26

25

26

24

24

24

25

26

22

29

29

29

29

26

29

28

28

28

28

As ppm

72

65

68

78

78

65

70

68

73

68

85

74

64

75

76

79

70

71

68

80

62

72

73

68

Ni ppm

12

12

12

12

13

12

12

13

13

12

13

12

12

12

13

12

13

13

12

13

12

12

13

12

Au ppm

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

<8

Pb ppm

5500

5800

5800

5600

5700

5600

5700

5800

5800

5500

5600

5700

5700

5600

5700

5800

5600

5600

5800

5700

5500

5500

5600

5700

Ba ppm

920

900

930

930

900

850

840

960

950

890

910

820

900

830

900

910

940

920

900

920

910

890

820

850

Sc ppm

22

24

23

22

20

22

23

21

21

21

21

22

22

22

23

26

26

25

24

25

25

25

24

23

Be 

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

ppm

Srppm

220

210

220

210

210

210

220

210

210

210

210

210

210

210

220

220

220

220

220

220

230

220

220

220

Cd ppm

13

13

13

12

12

12

12

13

13

13

12

13

12

12

13

13

12

12

12

13

12

12

12

13

Thppm

5

6

6

6

5

11

10

11

10

9

11

10

11

11

10

6

6

6

6

6

6

6

5

5
TiTiTiTiTiTiTiTiTiTiTiTi"n"n"n"nTiTiTiTiTiTiTiTi

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fO ^* (J CO OQ *s4 O) Ol Is* CO nj * ^D CO

en en -» ^ o) bo KJ o) bo <o ^ o <o ^ <o bo <o jt bo <o ^ 'o

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en en en en en en en en en en

oooooooooooooooooooooooo

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oooooooooooooooooooooooo

en *^ eo en ^s en ^^ c^ e?)

en en ^ -si <o o o -* -* o> -» lu w ^ en * o o <o o -»

-vi 6) 6) o> en ^i ^i ^i o> o> en

eoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeoeo

8 8 ft 81 2 SQ g 5e S SQ 2 81 8 8 SO 8 2 8 8 83 S 85 8 2

 Ck.tk.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck.Ck

_ >

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Z 

(0 

H 

(0

O
Appendix D. USGS single element results for NIST SRM 2780 

Lab No___As, ppm Se, ppm Hg, ppm Ctot % Stot %

F-027742

F-027741

F-027740

F-027739

F-027738

F-027737

F-027736

F-027735

F-027734

F-027733

F-027732

F-027731

F-027730

F-027729

F-027728

F-027727

F-027726

F-027725

F-027724

F-027723

F-027722

F-027721

F-027720

F-027719

44

42

47

47

42

46

44

44

46

47

43

38

42

51

41

45

38

42

42

38

45

40

41

49

4.8

4.9

5.2

5.1

5.1

5.1

5.1

5.1

5.1

5.2

5.2

5.2

5.2

5.3

5.0

5.3

5.2

5.0

5.2

5.2

5.1

5.3

5.3

5.3

0.65

0.72

0.70

0.69

0.72

0.65

0.72

0.67

0.72

0.66

0.79

0.67

0.84

0.70

0.65

0.73

0.69

0.68

0.90

0.87

0.69

1.1

0.63

0.72

0.19

0.17

0.16

0.17

0.17

0.18

0.17

0.17

0.17

0.17

0.17

0.17

0.16

0.17

0.16

0.17

0.17

0.17

0.17

0.2

0.17

0.17

0.17

0.2

1.24

1.21

1.23

1.22

1.23

1.23

1.21

1.24

1.21

1.24

1.21

1.22

1.21

1.21

1.22

1.21

1.23

1.24

1.23

1.23

1.24

1.24

1.26

1.26

14
Appendix E. Contract lab single element results for NIST SRM 2780

Lab No. 

Method

C-1 

C-115707 

C-115714 

15703 

C-1 

C-115715 

15710 

C-1 15698

As ppm 

(5)

54.2 

48.8 

55 

50.8

48.1 

53.5 

AU 

(4)

ppm 

0.199

0.152 

0.188 

0.217 

0.199 

0.261 

Cco3 

(2)

0.01

0.01 

0.01 

0.01 

0.01 

0.01 

Corg %

0.14

0.16 

0.19 

0.15 

0.15 

0.18 

Ctot % 

(1)

0.15

0.17 

0.20 

0.16 

0.15 

0.19 

FeO % 

0.7

0.7 

0.7 

0.7 

0.7 

0.6 

(2)

Hg ppm 

(3)

0.79

0.66 

0.51 

0.76 

0.69 

0.73 

Sb ppm 

121

106 

133 

129 

130 

129 

(5)

Se ppm 

3.8

4.5 

4.6 

4.0 

4.4 

4.8 

(5)

Stot % 

(1)

1.32 

1.3 

1.31

1.28 

1.24 

1.31 

Te 

4

5

5

5

4

5

(

1 LECOComblR

2 Potentionmetric titration

3 Cold Vapor AAS

4 Fire Assay

5 Hydride generation AAS

6 Graphite furnace-AAS

7 INAA

15