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Coneto Barsele QA/QC Procedures
Orex Minerals Inc. Orex Minerals Inc.
QA/QC Procedures
Quality Assurance / Quality Control Procedures for the Drilling Program at Coneto

Sound QA/QC procedures are important both for the company to know what is happening with the samples and for the investors to know that industry "Best Practices" are being met or exceeded.

The following points illustrate the path samples follow from initial core drilling to final announcement of results:

On The Property

  1. Drill hole locations are laid out in the field by Orex geologists. Pad construction, and later reclamation, is supervised by Orex staff and fore-sight / back-sight markers are set to align the direction of drilling.
  2. Drilling is being conducted by Major Drilling de Mexico S.A. de C.V., a subsidiary of Major Drilling Group International Inc., with experienced drillers. The drill is a skid-mounted UDR-200 MX #24 rig. The diamond drill core is HQ size, which provides a large sample as recommended for the testing of precious metal deposits.
  3. Down-hole surveys are conducted at 50 metre intervals down the drill hole using a Reflex survey device to measure azimuth and dip of the hole.
  4. It is the driller's responsibility to insure that the core in the boxes is in the correct order and to mark the length tags for each rod-length of core, as well as mark the inside of the core boxes where the tag is located. This step is examined by the on-duty project geologist.
  5. Core boxes are picked up from the drill site by Orex personnel and taken to the drill core logging facilities on the property.
  6. Boxes are then laid out on logging tables and checked to make sure that the core is continuous and in the right order in each box. Core boxes are cleaned at this stage to remove drill grease.
  7. Measurements of core between rod-length tags are taken to determine drill core recovery.
  8. The proportions of core fragments greater than 10 cm and 20 cm in length are determined to obtain RQD values. This data is entered into an RQD log. While this information will not be used in the exploration stage, it will be valuable information for future mine design indicating where competent ground and broken ground conditions can be expected.
  9. All core boxes and lids are then clearly labelled with the "from" and "to" lengths in metres.
  10. Geological logging of the core is conducted and sample positions are marked to conform with lithological / alteration changes. Sample numbers are written inside of the core boxes corresponding to pre-printed sample tags.
  11. Chalk lines are marked down the axis of the core and the boxes for sampling are moved to the cutting area. Diamond saw blade cutters are used to cut the core in half. This method is preferred over core splitters for precious metal deposits.
  12. The core boxes are returned to their places in order on the logging tables. Strong plastic rock sample bags are labelled with sample numbers on the outside and the sample tags inserted inside, then ½ the core is placed in their respective sample bags.
  13. The boxes from which samples have been taken are marked and placed in sequence on the core racks.
  14. The sample bags are moved to the testing table for determination of specific gravity. An SG value is determined for every sample and samples with high sulphide and/or barite content, or possessing extensive open-space vugs, are tested twice to confirm higher or lower SG readings. This information is used when determining tonnage.
  15. Geostandard samples are weighed and inserted every 10th sample as an analytical check for the laboratory batches. Geostandard "Orex-1" was prepared by SGS Mineral Services of quartz vein material from the Santa Cruz epithermal silver-gold project. Geostandards "Orko-8" and "Orko-10" were prepared by SGS Mineral Services of quartz vein material from the La Preciosa epithermal silver-gold project, each of which have undergone 5-lab analytical testing. Geostandard "Orex-Blank" is of barren andesitic rock and represents a laboratory blank sample.
  16. Sample bags are then closed and inserted in large sacks. These sacks are labelled with the sample range and company name, with the laboratory instruction sheet placed in sack #1 of the sampling batch.
Laboratories

The city of Durango, Mexico, is fortunate to have the services of several analytical laboratories, including the certified labs SGS Mineral Services and Inspectorate. Depending on the work loads of the labs, batches can be sent to either lab. SGS Lab in Durango has been selected for the beginning of the program.

  1. The sacks of samples are delivered by Orex personnel to the preparation laboratory of SGS Mineral Services in Durango, Mexico.
  2. From this point onward, SGS takes responsibility for the samples. SGS is an accredited and well respected analytical company. The Durango lab is where the samples are crushed and a sub-sample is pulverized. The pulverized pulp is placed in kraft sample bags and the un-pulverized portions are returned to the original sample bags.
  3. Orex personnel pick up the remainder of the crushed samples, referred to as "sample rejects", which are stored in Durango. The sample rejects are thus available for re-testing when required.
SGS Lab in Durango
  1. In Durango, the sample pulps are analysed by Inductively Coupled Plasma (ICP-14B) for 35 elements. Gold and silver are tested by Fire Assay, with an Atomic Absorbtion or Gravimetric finish depending on grade (FAG323) and silver is tested by Atomic Absorbtion Spectrometry (AAS). Each method has a lower and upper calibration range for which the results are accurately determined.
  2. Sample results falling out of the calibration range for the elements Au, Ag, Pb, Zn, Cu and As are re-analysed by methods with higher calibration ranges. This is true for silver >300 g/t, gold >10 g/t, and Pb, Zn, Cu and Ba >10,000 ppm.
  3. SGS also performs a "duplicate analysis" on every 12th sample, insuring that there is at least one duplicate run with every batch.
Orex in Vancouver and Durango
  1. Results are tabulated on spreadsheets and e-mailed to Orex geologists. Originals of the assay certificates are sent in hard-copy format to Vancouver.
  2. Upon receiving the completed analytical results, geologists then extract the duplicate and standard samples for examination of expected values versus tested values.
  3. The spreadsheet information for the drill hole samples is then matched with the sampling intervals and geological observations for interpretation.
  4. Results of the merged data are then sent to Orex management, along with the interpreted true width of the structures.
  5. Orex management periodically prepares news releases to make public the information from the drilling in a format compatible with NI 43-101 standards. A "Qualified Person" signs-off on news releases containing technical data.
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