Review by GRS of new data set of GIA (Reply).

GIA corrected on the 20th of December 2002 its original published data as following (same data set, using new standards). GRS has checked the report for accuracy.

GIA admits error in published data on new treatment. The errors in the data were attributed by GIA to lack of standards (e.g. no sufficient samples of known composition to compare with). Recalculating and using a new data set, correction were made on Be (40 times to high before), Fe (about 10 times to high before). Al is about 100times too low as it has to be close to 99.5% (526 600 ppm close to reality (GRS value), in comparison to approx. 6000ppm as stated in the former GIA report), GIA Titanium data seems to be 10 times too high as well (corrected old data not shown by GIA due to stated technical problems).

Still no information is made how exactly the new data are created, therefore, GRS cannot comment about the quality of the new and corrected data set. The concentrations in the new and corrected GIA data set, however, are within the same orders of magnitude than the one measured by GRS (see our table 1 & table 2). GIA mentioned in their report that the relative relationships between the values are still the same (before and after correction). This is not true for most cases, such as (same samples and same rough data set), Attention: ppm in weight not atomic (approximately):

Therefore, the old data were only qualitative data, after correction, the element ratios as well as absolute concentrations changed significantly, 1-2 order of magnitude.

Missing in GIA report: Methods with details, detection limits and errors (compare 1 & 2)

Suggestion: GIA data must still be ignored until methods and errors are discussed (see our article). Warning: Do not use the data of GIA in graphical presentations for origin of color discussions. Exact quantitative concentrations are essential for understanding the cause of color origin of this new treatment and to achieve such data, the quality of data must carefully be evaluated. However, the fact that Be diffused into the gemstones were discovered by GIA and this mechanism certainly play a role in the formation of the new color in the newly treated gemstones, upon which GRS agrees on.

Comment of R.Hughes to the original data of GIA, sited from Palagems website:

Quote: "It has been reported that the GIA's data is wrong. Is this true?
In the GIA's original report, an aluminum (Al) column was mistakenly included in one table, but that mistake in no way invalidated the other data obtained. Our current understanding is that all the data suggests that the yellow color of these stones is a result of outside-in diffusion of coloring agents (particularly beryllium)." End Quote

GRS does not further comment on R.Hughes-Palagems review of the GIA data. It seems that his information is not accurate in the context of the recent GIA publication.