BLM Assayer's report

Problems with inaccurate or non-reproducible assays caused the BLM Washington Office to assign the task of developing and implementing a scientific survey of assay laboratories' results to the National Training Center in Phoenix, Arizona.The project was assigned to Matthew W. Shumaker, Senior Geologist, and Burrett W. Clay, Supervisory Geologist. The survey was designed and commenced in late 1999. Laboratories were selected from their advertising in print, on the internet, and through professional contacts. In all 65 laboratories were tested, mostly in the United States and a few in Canada.

The majority of laboratories contacted had submitted their results by end of 2002. Several laboratories were surprisingly slow in producing results. As of the date of this report 1-27-03 reports still had not been received back from some laboratories.

One blank and three samples of known content were used in the test. Where possible, each laboratory was sent six blind samples, each numbered differently. The six samples included two duplicate samples of the blank, and two duplicate samples of the NBMG Standard Reference #6b. The duplicates were sent to test the laboratories ability to repeat results. If a laboratory cannot repeat an assay, all of their results are suspect.

The three standards used for this project were produced by the Nevada Bureau of Mines and Geology (NBMG). See attachment #5 in the report for information on the meticulous care that goes into preparing a standard. The three standards were named as follows:

NBMG Standard 4b - Consisted of pulverized and homogenized gold ore from the Mesquite mine in Southeastern California. - Attachment #1.
NBMG Standard 2b - Consisted of pulverized and homogenized gold ore from the Jerritt Canyon mine in Nevada. - Attachment #2.
NBMG Standard 6b - Consisted of pulverized and homogenized platinum & palladium ore from the J-M Reef at the Stillwater mine in Montana - Attachment #3. This sample was submitted in duplicate for testing for repeatability as were the blank samples.

The six samples combined into a "Suite". Each sample consisted of between 60 and 100 grams of material. Since a standard fire assay uses about 30 grams (an assay ton measure is 29.167 grams), it was believed this would be a sufficient amount of material. No laboratory had published required sample amounts beyond 90 grams. Several laboratories asked for a coffee can full or several pounds of the sample material. They were sent 90 to 120 grams and none asked for larger samples after receiving this amount.

The "Blank" material presented a problem. Normally silica sand would be used. When powdered it resembled powdered sugar and was a give-away that it was a blank material. With some ingenuity, one of the authors of this report gathered a quantity of material from some landscaping fill that was dumped in his front yard. This gave the authors a material that had the tan color of common mineral matter and additional dark pieces common to the igneous rocks in the area. Since the standard samples ranged from a buff to a dark gray, this landfill material effectively disguised the blank material. Since it contained the igneous material it was designated a "Complex Blank".

The complex blank was sent to seven major assay laboratories recognized by the mining industry for their reputability for analyses. These seven analyses showed the complex blank samples contained no gold, silver or platinum group metals (PGM) One laboratory, Bondar-Clegg did report 0.00015 of Au which was within the limits of expected average crustal abundance for this element.

Samples were submitted and payment was made for the analyses in a manner that would assure that the results reported would be the same as reported to any member of the general public.