Origin determinations of the AGL
An opinion of the geographic origin is based on a collection of observations and data collected on the gemstone being tested, which is compared to the knowledge and experience of the AGL staff for similar observations and data collected on gemstones of known geographic origin and published gemological literature.
This collection of observations and data includes but is not limited to: microscopy (inclusion patterns), identity and occurrence of mineral inclusions, internal growth structures and color zoning, UV/Vis/NIR spectroscopy, mid-infrared spectroscopy, Raman spectroscopy and semi-quantitative chemical analyses, etc. as required.
1) When a geographic origin is given: An origin declaration represents an expression of expert opinion based on experience and data collected from gemstones of known origin. When examining gemstones to determine their origin, the collection of observations and data can in some instances indicate more clearly the provenance or country of origin than others that are less clear. As a consequence, there are different levels of confidence inherent to this type of determination.
1a) Based on available gemological information: The comments under the Provenance section of an AGL report will start with this wording when the collection of observations, gemological data and experience of the examiner allows for a higher degree of confidence when making an origin declaration.
Comments: Based on available gemological information, it is the opinion of the Laboratory that the origin of this material would be classified as Burma (Myanmar).
1b) It is the opinion of the Laboratory, based on the weight of evidence: The comments under the Provenance section of an AGL report will start with this wording when the collection of observations and gemological data is suggestive of more than one source however the experience of the examiner indicates a particular source to be more probable.
Comments: It is the opinion of the Laboratory, based on the weight of evidence that the origin of this material would be classified as Burma (Myanmar).
2) When a currently undeterminable result is given: An origin declaration is based on the collection of information gathered from the gemstone being tested. Not each and every gemstone will provide enough information to allow for an origin declaration to be made. In addition, there are instances where the information collected is overlapping to a large extent between two or more geographic locations. As a consequence, the result indicated on an AGL report may also read as follows under the comments section of Provenance:
Comments: The country of origin for this stone is currently not determinable with a high enough degree of certainty.
3) When the term ‘Classic™’ is applied to an origin declaration on an AGL report: The term Classic™ is applied to an AGL report when you have the combination of two important attributes:
1) The origin determination is of a high confidence level
2) The quality of a given gemstone is top-quality. A gemstone exhibiting the kind of superior quality that helped to earn a particular source its name and reputation in the industry.