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Reference Materials...
Click on any "Reference Material" text below
to see the full range of Reference Materials available at Rocklabs
or click here.
What Are They?
Pulverized rock with known gold content and suitable for analysis
by fire assay or aqua regia digest. These are
low cost, quality control aids used on an "every batch" basis
to monitor the analytical process They can be used
by laboratories or by geologists who can submit Reference
Materials in sachets together with their samples to
laboratories.
How Are They Prepared?
These Reference Materials (also known as standards) are prepared
from mineral matrices that contain gold
which is uniformly distributed throughout the pulverized rock.
Once appropriate material has been prepared
and been confirmed as suitable by laboratory analysis it is packaged
in to sachets or jars. A full homogeneity
test is then carried out on a representative number of sub-samples
from the packaged batch. If there is no
significant difference found between the sub-samples then the gold
content is determined by consensus testing
using a minimum of 15 reputable laboratories from several different
countries. Standard statistical techniques
are used to assign a recommended gold value with associated 95%
confidence interval. Each sachet or jar is
labeled with a unique number. A certificate, which includes details
of the production and characterization of
the Reference Material, is issued with each consignment of sachets
or jars sold
Who Can Use Them?
Laboratories will use them as part of their normal quality control
process. Competent laboratories already do
this but often they use "standards" which they have made
themselves and which have not been subjected to
rigorous homogeneity tests or had the gold concentration accurately
determined through analysis by a large
number of quality laboratories. Sachets are supplied with a "Labcheck" label
when used by laboratories as part
of their own quality-monitoring program. Laboratories may prefer
to use Reference Materials packed in wide mouthed
jars and which contain 2.5kg. Jars of Reference Material have been
tested to check that the gold does
not settle out from vibrations, eg during transport.
Exploration
and mine geologists can submit one sachet (option of 30g or 50g
sizes available) with every batch of samples they send to the laboratory
for gold analysis. If they send large batches they may choose to
include one sachet with every 50 samples submitted. The sachets
are robust and can be "thrown" in with their
other samples. Because the sachets are sealed it does not matter
if they get dirty or wet on the outside. Sachets
are supplied with a "Geocheck" label when used by geologists
submitting samples to a laboratory. They have a
unique number on every sachet, but do not have the name of the Reference Material on the label.
Advice on the use of Reference Materials
ROCKLABS has a team of chemists, geologists and a statistician
to advise on the use of ROCKLABS
Reference
Materials and the analysis of analytical results. All
users of our Reference Materials are encouraged to
use our template to plot Reference
Materials analytical results.
To obtain our template, with user instructions and worked examples,
or if you wish to have advice on the
selection or use of ROCKLABS Reference
Materials, please contact:
Roger Gregg Malcolm Smith
MSc (Hons) MAusIMM BSc FNZIC
r.gregg @ rocklabs.com malcolm @ msrml.co.nz
For more details of Rocklabs Reference
Materials, please contact
the ROCKLABS team.
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