PRELIMINARY - U.S. Geological Survey Certificate of Analysis

Granodiorite, Silver Plume,Colorado, GSP-2

Material used in the preparation of GSP-2 was collected by the U.S. Geological Survey, from the Silver Plume Quarry, which is located approximately 800 meters west of Silver Plume, Colorado. This is same location used to provide material for GSP-1. GSP-2 is a medium grained hypidiomophic- granular rock consisting essentially of quartz, plagioclase, microcline, biotite, and muscovite. Details of the collection, preparation, and testing are available (Wilson, S.A., 1998).

Element concentrations were determined in a round robin study involving 20 international laboratories. Recommended values are listed when analytical results provided by three independent laboratories using a minimum of three independent analytical procedures are in statistical agreement. Information values with standard deviations are listed when at least four independent laboratories using two independent analytical procedures have provided information. Information values without standard deviations represent information from a single laboratory or analytical procedure.

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


Element Wt % ± Oxide Wt % ±
Al 7.88 0.11 Al2O3 14.9 0.2
Ca 1.50 0.04 CaO 2.10 0.06
Fetot 3.43 0.11 Fe2O3 tot 4.90 0.16
K 4.48 0.12 K2O 5.38 0.14
Mg 0.58 0.02 MgO 0.96 0.03
Na 2.06 0.07 Na2O 2.78 0.09
P 0.13 0.01 P2O5 0.29 0.02
Si 31.1 0.4 SiO2 66.6 0.8
Ti 0.40 0.01 TiO2 0.66 0.02
Element µg/g ± Element µg/g ±
Ba 1340 44 Pb 42 3
Ce 410 30 Rb 245 7
Co 7.3 0.8 Sc 6.3 0.7
Cr 20 6 Sm 27 1
Cu 43 4 Sr 240 10
Eu 2.3 0.1 Th 105 8
Ga 22 2 U 2.40 0.19
La 180 12 V 52 4
Mn 320 20 Y 28 2
Nb 27 2 Yb 1.6 0.2
Nd 200 12 Zn 120 10
Ni 17 2 Zr 550 30

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Information Values

Element µg/g ± Element µg/g ±
Be 1.5 0.2 Ho 1.0 0.1
Cs 1.2 0.1 Li 36 1
Dy 6.1   Lu 0.23 0.03
Er 2.2   Mo 2.1 0.6
F 3000   Pr 51 5
Gd 12 2 Ti 1.1  
Hf 14 1 Tm 0.29 0.02

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Certificate Information

Denver, Colorado
November 1998

Dr. Linda Gunderson
Central Region Mineral Resources Team

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Bibliography

Wilson, S.A., 1998, Data compilation for USGS reference material GSP-2, Granodiorite, Silver Plume, Colorado: U.S. Geological Survey Open-File Report (in progress).

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Glossary

Symbol Definition
Wt % Weight percent of element/oxide as received
µg/g Micrograms of element per gram of sample, as received
± One standard deviation

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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)

Payment Options

Domestic customers: Payment options include purchase order, check, money order, or credit card (Visa, Mastercard, American Express).

International customers: Payment on foreign orders can only be made using the following:

  • Banker's draft against an international bank
  • International money order
  • Credit card (Visa, Mastercard, American Express)

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

User Agreements

Beginning in 2006, users of USGS geochemical reference materials must complete a user agreement form prior to the order being processed. This agreement is required by the USGS Technology Transfer Office for complying with the United States Economy Act, 31 USC 1535A.

Please download the agreement form and follow the instructions on the form when placing your order.

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