U.S. Geological Survey Certificate of Analysis

Diabase, W-2

Material was collected in 1976 from the Bull Run quarry near Centreville, Virginia. This is the same collection site as USGS reference mateirals W-1 (Fairbairn, 1950). The diabase consists of augite and plagioclase with smaller amounts of quartz, potassium feldspar, biotite and opaque minerals.

Recommended Concentrations

Values listed are derived using at least two independent techniques from at least two independent laboratories. Statistical treatment of the data uses the procedures outlined in previous USGS publications (Flanagan and Gottfried, 1980). Supplemental information is derived from international data compilations (Gladney and Roelandts, 1988, Govindaraju, 1994,).

Information values

Values are presented when only a single method of analysis was used or results from independent laboratories are not in statistical agreement.

Recommended Values | Information Values | Certificate Information | Bibliography | Glossary | Notes | Order and Pricing Information


Oxide Wt % ± Oxide Wt % ±
Al2O3 15.45 0.16 MgO 6.37 0.058
CaO 10.86 0.078 MnO 0.167 0.004
Fe2O3 1.53 0.87 Na2O 2.20 0.037
FeO 8.34 0.093 P2O5 0.14 0.12
Fe2O3T 10.83 0.21 SiO2 52.68 0.29
K2O 0.626 0.012 TiO2 1.06 0.01
Element µg/g ± Element µg/g ± Element µg/g ±
Ba 170 11 Hf 2.6 0.18 Sr 190 3
Ce 23 1.5 La 10 0.59 Th 2.4 0.1
Co 43 2.1 Li 9.6 0.54 V 260 12
Cr 92 4.4 Nd 13 1 Y 23 1.6
Cu 110 4.9 Ni 70 2.5 Yb 2.1 0.2
Dy 3.6 0.8 Rb 21 1.1 Zn 80 2
Eu 1.0 0.06 Sc 36 1.1 Zr 100 2
Ga 17 0.89 Sm 3.3 0.13

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Information Values

Element µg/g Element µg/g Element µg/g
As 1.2 F 205 Sb 0.79
B 12 Ho 0.76 Ta 0.5
Be 1.3 Lu 0.33 Tb 0.63
Cl 190 Nb 7.9 Tm 0.38
Cs 0.99 Pb 9.3 U 0.53
Er 2.5 Stot 79

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Certificate Information

Denver, Colorado
revised March 1995

David B. Smith
Central Region Mineral Resources Team (formerly Branch of Geochemistry)

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Bibliography

Flanagan, F.J., and Gottfried, D., 1980, USGS rock standards III; Manganese-nodule reference samples USGS NOD-A-1 and USGS-NOD-P-1: U.S. Geological Survey Professional Paper 1155, 39 p.

Flanagan, F.J., 1984, Three USGS Mafic Rock Reference Samples, W-2, DNC-1, and BIR-1: U.S. Geological Survey Bulletin 1623, p. 54.

Gladney, E.S., and Roelandts, I., 1988, 1987 Compilation of Elemental Concentration Data for USGS BIR-1, DNC-1, and W-2: Geostandards Newsletter, 12:63-118.

Govindaraju, K., 1994, 1994 Compilation of Working Values and Descriptions for 383 Geostandards: Geostandards Newsletter, 18:1-158.

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Glossary

Symbol Definition
Fe2O3T Total iron expressed as Fe2O3
Ctot Total carbon concentration
Stot Total sulfur concentration
Wt % Percent of total element concentration
µg/g Total element concentration expressed as micrograms of element per gram of solid sample
± One standard deviation

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Notes

Unless otherwise indicated total element concentrations are reported for material on an as-received basis, i.e., no drying.

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Order and Pricing Information

Placing an Order

USGS reference materials may be obtained directly from Dr. Stephen A. Wilson. The price for each reference material is listed in U.S. dollars and are subject to change. For domestic orders, this cost includes all shipping and handling charges using normal mail delivery by the U.S. Postal Service. For foreign orders, delivery charges will be added to the final bill. Urgent requests for reference materials should be initiated by Fax or e-mail. If required, expedited delivery is available with any additional shipping charges added to the final bill.

To order a USGS Reference Material, please contact Dr. Stephen Wilson or use the downloadable form: Order Form (Word) (22 KB) or Order Form (PDF) (238 KB).

Dr. Stephen A. Wilson
U.S. Geological Survey
Box 25046, MS 964D
Denver, CO 80225
Tel: 303-236-2454
FAX: 303-236-3200 or 303-236-1425
Email: (swilson@usgs.gov)

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Payments for domestic or international orders using a credit card receive a 10% discount on the per bottle price.

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