Thomas Gilbert
Round Robin Committee - Chairman

What is the Gold Round  Robin?

The Gold Round Robin is a means for SMA members to assess the quality of their  analytical technique.  This is accomplished by the exchange of samples between  participating laboratories.  These participating laboratories then analyze the  samples for gold content. Participating laboratories can be either an analyzing laboratory  or a shipping & analyzing laboratory. But more about that later.

The program can be summarized with the following points:

• Six samples in each shipment
• Six shipments per year
• You are given four weeks to analyze the samples
• The data is reported graphically and with a  summary statistical analysis

Who Can Participate?

Any Laboratory, either Commercial or Private can participate in the round-robin.  However, your laboratory should contain at least one "Society of Mineral Analysts" member that is in good standing (that means with paid dues).  It is most helpful if the contact person at each laboratory is an SMA member.  This will  promote unity among the participants and assist me in getting information out to you.

One important thing to be aware of if you participate in the round-robin: The data that is  included in each report is referenced to the participating laboratory that performed the  analysis.  In other words, this is not a secret ballot type of round-robin.  On  the positive side, if your lab performs well everyone will know it.  On the bad side,  if your lab is off in left field ......

You have two ways of participation.  You can agree to only be an analyzing laboratory  or you can be included also as a sample shipper.  Shippers have the benefit of  comparing themselves to other laboratories on there own material.  This factor alone  can carry a great deal of weight when upper management wants to question your assays.

If you are a shipper you can say to the boss: "Twenty other labs had  the same assay as we did on our monthly mill composite we included in the SMA round-robin last month"

Then the boss might say: "Great, keep up the good work!"

If you are not a shipper you can say to the boss: "Twenty other labs had the same assay as we did on that half ounce oxide sample"

Then the boss might say: "That's nice, if we ever have any samples that are something other than low grade sulfides, I'll know that you can assay them okay."

Then you say: "Well, next month AJAX Gold Corporation is the shipper and there ore is like ours."

I don't know about you but I like to hear the first response occasionally.  I realize that it is not possible for all the laboratories to be shippers.  But consider two additional factors. Being a shipper is a very cheap way to have  a large number of laboratories assay a material you might want to use as a in-house  reference material.

How do I Participate?

Contact: Tom Gilbert
(775) 758-9221 x151

What Types Of Samples Are  Included?

There are up to three different materials included in each shipment. With each sample sent in duplicate.  The samples can be pulverized geological material, activated carbon, reference materials, mill samples, processing concentrates, etc.

A Note to Shippers of Geological Materials:

The grade of the pulp samples is open to your discretion. This material should be pulverized to at least a minimum of -100  mesh and well blended so that it is as homogenous as possible. Please note that your samples will not be returned.

A Note to Shippers of Activated Carbon:

The grade of the activated carbon sample is open to your discretion. The samples can be either loaded, stripped, or somewhere in between. The activated carbon should not be  pulverized and it should be free of any extraneous matter such as rocks or wood chips.    Please note that your samples will not be returned.

A Note to Shippers of Process Concentrates:

The grade of the sample is open to your discretion.  The samples can include such  things as Floatation Concentrates, Merrill Crowe Precipitates, or Gravity Concentrates.  Please do not send Bullion. The material should be as fine as possible in order to obtain representative sub-samples.  Please note that your samples will not be returned.

How Should The Samples Be Labeled?

The samples should be labeled in the following manner:

    Samples 1 & 2
            "XXX 1A"
            "XXX 1B"

    Samples 3 & 4
            "XXX 2A"
            "XXX 2B

    Samples 5 & 6
            "XXX 3A"
            "XXX 3B
 

The "XXX" is for three characters that you can use as code letters to identify  your company.  For example: "NGC" as in Newmont Gold Company or  "MMC" as in Marigold Mining Company.

How Should The Samples Be  Packaged?

The sample itself should be in one four types of containers:

• Plastic Bottle or Tub
• Plastic Bag or Envelope
• Paper Envelope
• Glass Bottle

From personnel experience the more layers the better.  Plastic bags or paper envelopes are the most economical and the easiest  to handle.  Note, however, that paper envelopes will tear if they are not packaged together securely.

The samples can be shipped in several different types of containers:

• Cardboard Box
• Paper Envelope
• Padded Paper Envelope
• Metal Can

Paper envelopes are generally not secure enough.  Cardboard boxes work well if you add extra packing to fill the empty space.  Padded paper envelopes work quite well if the samples themselves are packaged securely and if the envelope is not to big.  Because of the cost only use metal cans when sending out hazardous materials or as required by law.

How Should Samples Be  Shipped?

You have great deal of latitude as to the shipping of samples.  This is purely up to you and your company.  Most shippers in the past have typically used the United States Postal Service (USPS) or United Parcel Service (UPS).

What Will The Data Output  Look Like?

The data presentation is divided into two parts, statistical tabulation and graphics.  Examples of each are attached to this report. See below for a description of each.

Statistical Tabulation:
The statistical tabulation includes the following:

• Raw data on all six samples from each laboratory  that participated.
• A set of descriptive statistics on each sample. This  includes:
• Mean
• Kurtosis
• Standard Error
• Confidence Level of the Mean
• Skewness
• Range
• Median
• Mode
• Minimum
• Maximum
• Standard Deviation
• Variance
• Count

Graphics:
The graphical analysis will be performed for each sample.  Currently this is a simple  scatterplot of assay results verses laboratory.  It shows three items in addition to the data for each laboratory.

• The Group Mean
• A 95% Confidence Interval Limits for the Group Mean
• 2 times the Standard Deviation of the Group Data

What this means is that if your laboratory is within the Confidence Intervals you performed very well on your assay.  If you  were outside the Confidence Interval but inside the 2x STD you performed fairly well on your assay.  If you were outside the 2x STD you may have some serious problems to  address.