Ophir delivers a complete range of services, from refining to the manufacture of cast bars, assaying, as well as design and manufacture of coins, medals and jewelries. Ophir Clients include mining companies, jewelry manufacturers, domestic and international banks, Governments and Central Banks.

Assaying

Service Overview

Ophir operates a state-of-the-art testing laboratory. Our testing methods are accredited. All sampling and testing activities are performed by independent certified precious metals assayers in compliance with the Liberia Minerals Law of Precious Metals and supervised by Ministry of Mines and Energy. A highly qualified professional team carries out a whole range of analyses to ensure Ophir always meets both production and environmental standards of excellence.
Our laboratory employs a comprehensive range of testing techniques as e.g. traditional Fire Assay, potentiometric methods, XRF, SPARK and ICP spectrometry. Testing methods are applied on a case-by-case basis and may include various testing techniques, applied singly or in combination, as appropriate. We maintain close and effective communication with our Clients and their Representatives and cooperate closely with the Swiss public authorities.

ASSAYING ANALYSIS

  • 1st Phase
  • 2nd Phase
  • 3rd Phase
  • 4th Phase
  • 5th Phase
  • 6th Phase
  • 7th Phase

The laboratory shall clean and drill the samples, putting the drillings from each sample into separate envelopes. The laboratory shall then analyze each individual sample to verify the homogeneity of the melt. If homogeneity is verified and there is an agreement for exchange of assays between the Client and Ophir, three equal final samples of usually 5-10 grams each shall be prepared with the drillings of the sample taken from the melt just before pouring. If homogeneity cannot be proved the lot shall be re-melted.

The obtained samples are sealed by the Representative, labelled with the melt number and distributed as follows:

  1. a)One sealed sample is kept with Ophir at the Client’s disposal or delivered to its Representative, if present. Ophir will mail such sample to the Client or Client’s requested laboratory upon written instructions; 
  2. b)One of the sealed samples is kept at Ophir laboratory to perform the analysis;
  3. c)One of the sealed samples remains with Ophir for contingent Umpire assay.

Sampling of the recovery bar: the laboratory shall sample the recovery bar. The samples taken shall be put into separate envelopes, labelled with the melt number and the drilling side. The sample shall be analyzed by Golden Ophir to verify the homogeneity of the recovery bar.

Preparation and sealing of the final samples of the recovery bar: if homogeneity of the recovery bar has been proved, three sealed envelopes shall be prepared, containing each usually 5-10 grams of drilled material, after having mixed equal parts of the drillings taken from the recovery bar. The samples obtained from the recovery bar are sequentially stored with the other samples.

Assays: the assays shall be carried out by the fire assay method. Results of such assays shall be exchanged simultaneously between Client and Ophir by mail, on a date to be agreed upon and followed by fax or e-mail the following day. Should the difference between the exchanged results not exceed the Splitting Limits, then the arithmetic mean of the results of Ophir and Client shall be taken as final.

Splitting Limits: subject to exchange of assays being contractually agreed upon the splitting limits are usually: 0.05% for Au and 0.20% for Ag in case of gold base material; 0.03% for Au and 0.20% for Ag in case of silver base material. For Pt and Pd Ophir's assays will be final and binding.

Assay results shall be expressed to four (4) significant figures for 995,0 and higher fineness and five (5) significant figures for gold below 995,0 fineness.

Umpire

  1. a) If the difference between the assays exceeds the splitting limits, both Client and Ophir shall have the right to ask for assays to be remade or to request an umpire analysis.
  2. b)The second assay or the Umpire analysis, if requested, has to be initiated within 4 (four) Business Days after the request is made.
  3. c)The Umpire assayer shall not be the Representative of Client or Ophir.
  4. d)The Umpire assayer shall be one of the firms previously agreed upon on a rotational basis and shall use the fire assay method. Any other organization may be designated as Umpire assayer by Client and Ophir from time to time upon mutual agreement.

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About Our Company

Ophir delivers a complete range of services, from refining to the manufacture of cast bars, assaying, as well as design and manufacture of coins, medals and jewelries. Ophir Clients include mining companies, jewelry manufacturers, domestic and international banks, Governments and Central Banks.
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