Does anyone know if this is still a worry if buying diamonds which are being posted abroad? This article appeared after September 11th.
Gem and Jewelry Trade Alert
U.S. Postal Service Irradiation Process
May Affect Some Gemstones
By Shane F. McClure, Thomas M. Moses and John I. Koivula
GIA Gem Trade Laboratory
The jewelry industry relies heavily on the U.S. Postal Service to ship gems and jewelry throughout the United States. As most are aware, the recent incidences of people being infected by anthrax spores sent through the mail has caused the USPS to seek ways to protect postal employees and the public from this potential threat. One part of this effort is to use a technique that actually kills anthrax spores (and other biological agents) in the mail as it is being processed.
One company with which the postal service has contracted, SureBeam (a subsidiary of Titan Corp.), makes equipment designed to combat food-borne pathogens such as salmonella. SureBeam provides a type of linear accelerator that creates a beam of high-energy electrons. In effect, they are using irradiation to kill the microorganisms that often contaminate food.
However, we know that this type of ionizing radiation is often used intentionally to change the color of some gem materials—and could produce an undesirable result as well. We at GIA and others in the trade immediately recognized the potential impact of this development on the jewelry industry and the consuming public, so we decided to test the effect of the proposed postal irradiation process on gem materials.
The Process
A spokesman for SureBeam told us that the actual dosage being used by the postal system is 56 kilograys, which is equivalent to 5.6 megarads. This figure was later confirmed by Laura Smith, Quality Assurance Manager for Titan Scan Technologies, another Titan Corp. subsidiary, who agreed to run tests for us under the same conditions that are being used by the post office.
For these initial tests, we chose gem materials that, based on our many years of experience and discussions with experts in the field, we know to be affected by irradiation in a significant way. This group consisted of two types of cultured pearls plus eight different gem species and a number of varieties of those species—all of which were natural—for a base of 16 different samples, as follows:
Diamond - near colorless
Diamond - gray (due to inclusions)
Kunzite
Morganite
Cultured Pearl - bead-nucleated saltwater
Cultured Pearl - tissue-nucleated freshwater
Quartz - colorless
Quartz - yellow (citrine)
Sapphire - light blue
Topaz - colorless
Tourmaline - near colorless
Tourmaline - light pink
Tourmaline - bi-colored green and pink
Zircon - colorless
Zircon - yellow
Zircon - green
Of course, there are many other gem materials that might be affected by this process, and the same gem materials from different localities or with chemical or structural differences might not respond the same as our samples. We intend to follow up this initial study with one that will encompass many other species as well as stones of known geographic origin.
We also added to this group a 14 karat yellow gold ring, to reassure the industry that gold jewelry would not retain any residual radioactivity from this process.
We made up three sets of these samples and placed them in boxes that were packaged in the same manner that we routinely use to ship gems from the GIA Gem Trade Laboratory. Because stones are often shipped through the mail more than once (e.g., sent out on memo, returned or sent to a manufacturer for mounting, and then sent back or on to someone else), we asked to have one package scanned just once, another scanned twice, and the third scanned four times—to see if the cumulative effect of multiple scans caused any significant difference.
The contents of the boxes were identical, except there was only one heavily included gray diamond. We placed this in the package that was to receive four scans to confirm that it would not retain any residual radioactivity, as is often detected in irradiated black diamonds.
Results
After we retrieved the packages, we first checked for the presence of residual radiation with a Victoreen model 290 radiation survey meter. This was done on the unopened packages as well as on the individual samples. Fortunately, no residual radiation was detected.
Next, we examined all the individual stones for obvious changes in appearance. (Changes in spectra and analytical data will be addressed in the course of future research.). All of the gem materials other than diamond showed a dramatic change in color, as described below:
Gem Material
Before After
Diamond near colorless near colorless -
no change
Diamond gray gray - no change
Kunzite pink green
Morganite brownish or
orangy pink yellow
Cultured Pearl,
saltwater white gray
Cultured Pearl,
freshwater white gray
Quartz colorless brown
Quartz yellow brown
Sapphire light blue yellowish orange
Topaz colorless brown
Tourmaline near colorless light pink
Tourmaline light pink darker pink
Tourmaline bi-colored green
and pink green - no change
pink - darker
Zircon colorless pinkish brown
Zircon yellow yellowish brown
Zircon green (greenish) yellowish brown
Before-and-after images of the freshwater cultured pearls, kunzite, and sapphire illustrate some of the significant changes we observed (see figure).
Gem materials before (left) and after (right) irradiation by current postal sanitization procedures: (top) freshwater cultured pearls, (middle) kunzite, and (bottom) sapphire. Photos by Maha Tannous.
We did not separate out the results for one, two, or four scans because, for most of the samples, the changes were just as dramatic in the box that went through only one scan as in the box that went through four. However, the
degree of change was different for some stones. For example, the colorless quartz in the box that was scanned once came out a medium brown; a similar sample in the box scanned twice turned dark brown; and the third sample, scanned four times, became almost black. For the other gems, there was no visible difference related to the number of scans.
Implications for the Future
Currently, the U.S. post office is scanning only a small portion of the mail and only letters and flat envelopes. John Dunlap, Manager of Materials Handling and Deployment for the USPS Engineering Group, which oversees mail sanitization operations, told us that "Probably nothing will be done to packages that are sent registered or certified [the preferred method for the jewelry industry], since we now require information from the sender." Other postal authorities have commented that the cost and time required to scan all mail would be prohibitive
We also contacted the U.S. Customs Service, Brinks, Malca Amit, UPS, and FedEx to see if they were currently using sanitization procedures or had plans to do so. They all stated that no irradiation procedures were being used or were planned at this time. They all have imposed stricter limitations with letters, and some of the shippers are no longer transporting envelopes. Nevertheless, it is important that members of the trade and the consuming public alike be aware that some gem materials could be affected by the procedure, and every effort should be made to ship such materials by methods that are not likely to be exposed to the sanitization process.
Note, too, that some of the color changes seen in our samples would not be permanent. Some of these colors will fade with exposure to light back to their original colors. Others can be changed back with heat. Still others will never revert to their original color. (For more on the color stability of irradiated gems, see K. Nassau, Gemstone Enhancement, 2nd ed., Butterworth-Heinemann, Oxford, 1994.)
Also as mentioned above, not all members of the same species or even the same variety will react similarly. For example, according to Dr. George Rossman of the California Institute of Technology, it is less likely that blue sapphires from basaltic deposits such as Thailand or Australia will change.
We recognize that other gem species or varieties, including ruby and emerald, may be affected to lesser degrees by this radiation dosage. In the second phase of our testing, which is already underway, we hope to answer this and many more questions about this newest concern to the industry.
For background information on commercial irradiation of gem materials, see
C. E. Ashbaugh, "Gemstone Irradiation and Radioactivity," Gems & Gemology, Winter 1988, pp. 196-213. For more on the possible effects of postal sanitization on gem materials, see the upcoming Winter 2001 issue of Gems & Gemology.
Here is the link I found this at
http://www.diamondtalk.com/forums/showthread.php?t=11358&highlight=US+postal+scanning
According to forum replies it appears it is not much of a hazard to the stones.
Gem and Jewelry Trade Alert
U.S. Postal Service Irradiation Process
May Affect Some Gemstones
By Shane F. McClure, Thomas M. Moses and John I. Koivula
GIA Gem Trade Laboratory
The jewelry industry relies heavily on the U.S. Postal Service to ship gems and jewelry throughout the United States. As most are aware, the recent incidences of people being infected by anthrax spores sent through the mail has caused the USPS to seek ways to protect postal employees and the public from this potential threat. One part of this effort is to use a technique that actually kills anthrax spores (and other biological agents) in the mail as it is being processed.
One company with which the postal service has contracted, SureBeam (a subsidiary of Titan Corp.), makes equipment designed to combat food-borne pathogens such as salmonella. SureBeam provides a type of linear accelerator that creates a beam of high-energy electrons. In effect, they are using irradiation to kill the microorganisms that often contaminate food.
However, we know that this type of ionizing radiation is often used intentionally to change the color of some gem materials—and could produce an undesirable result as well. We at GIA and others in the trade immediately recognized the potential impact of this development on the jewelry industry and the consuming public, so we decided to test the effect of the proposed postal irradiation process on gem materials.
The Process
A spokesman for SureBeam told us that the actual dosage being used by the postal system is 56 kilograys, which is equivalent to 5.6 megarads. This figure was later confirmed by Laura Smith, Quality Assurance Manager for Titan Scan Technologies, another Titan Corp. subsidiary, who agreed to run tests for us under the same conditions that are being used by the post office.
For these initial tests, we chose gem materials that, based on our many years of experience and discussions with experts in the field, we know to be affected by irradiation in a significant way. This group consisted of two types of cultured pearls plus eight different gem species and a number of varieties of those species—all of which were natural—for a base of 16 different samples, as follows:
Diamond - near colorless
Diamond - gray (due to inclusions)
Kunzite
Morganite
Cultured Pearl - bead-nucleated saltwater
Cultured Pearl - tissue-nucleated freshwater
Quartz - colorless
Quartz - yellow (citrine)
Sapphire - light blue
Topaz - colorless
Tourmaline - near colorless
Tourmaline - light pink
Tourmaline - bi-colored green and pink
Zircon - colorless
Zircon - yellow
Zircon - green
Of course, there are many other gem materials that might be affected by this process, and the same gem materials from different localities or with chemical or structural differences might not respond the same as our samples. We intend to follow up this initial study with one that will encompass many other species as well as stones of known geographic origin.
We also added to this group a 14 karat yellow gold ring, to reassure the industry that gold jewelry would not retain any residual radioactivity from this process.
We made up three sets of these samples and placed them in boxes that were packaged in the same manner that we routinely use to ship gems from the GIA Gem Trade Laboratory. Because stones are often shipped through the mail more than once (e.g., sent out on memo, returned or sent to a manufacturer for mounting, and then sent back or on to someone else), we asked to have one package scanned just once, another scanned twice, and the third scanned four times—to see if the cumulative effect of multiple scans caused any significant difference.
The contents of the boxes were identical, except there was only one heavily included gray diamond. We placed this in the package that was to receive four scans to confirm that it would not retain any residual radioactivity, as is often detected in irradiated black diamonds.
Results
After we retrieved the packages, we first checked for the presence of residual radiation with a Victoreen model 290 radiation survey meter. This was done on the unopened packages as well as on the individual samples. Fortunately, no residual radiation was detected.
Next, we examined all the individual stones for obvious changes in appearance. (Changes in spectra and analytical data will be addressed in the course of future research.). All of the gem materials other than diamond showed a dramatic change in color, as described below:
Gem Material
Before After
Diamond near colorless near colorless -
no change
Diamond gray gray - no change
Kunzite pink green
Morganite brownish or
orangy pink yellow
Cultured Pearl,
saltwater white gray
Cultured Pearl,
freshwater white gray
Quartz colorless brown
Quartz yellow brown
Sapphire light blue yellowish orange
Topaz colorless brown
Tourmaline near colorless light pink
Tourmaline light pink darker pink
Tourmaline bi-colored green
and pink green - no change
pink - darker
Zircon colorless pinkish brown
Zircon yellow yellowish brown
Zircon green (greenish) yellowish brown
Before-and-after images of the freshwater cultured pearls, kunzite, and sapphire illustrate some of the significant changes we observed (see figure).
Gem materials before (left) and after (right) irradiation by current postal sanitization procedures: (top) freshwater cultured pearls, (middle) kunzite, and (bottom) sapphire. Photos by Maha Tannous.
We did not separate out the results for one, two, or four scans because, for most of the samples, the changes were just as dramatic in the box that went through only one scan as in the box that went through four. However, the
degree of change was different for some stones. For example, the colorless quartz in the box that was scanned once came out a medium brown; a similar sample in the box scanned twice turned dark brown; and the third sample, scanned four times, became almost black. For the other gems, there was no visible difference related to the number of scans.
Implications for the Future
Currently, the U.S. post office is scanning only a small portion of the mail and only letters and flat envelopes. John Dunlap, Manager of Materials Handling and Deployment for the USPS Engineering Group, which oversees mail sanitization operations, told us that "Probably nothing will be done to packages that are sent registered or certified [the preferred method for the jewelry industry], since we now require information from the sender." Other postal authorities have commented that the cost and time required to scan all mail would be prohibitive
We also contacted the U.S. Customs Service, Brinks, Malca Amit, UPS, and FedEx to see if they were currently using sanitization procedures or had plans to do so. They all stated that no irradiation procedures were being used or were planned at this time. They all have imposed stricter limitations with letters, and some of the shippers are no longer transporting envelopes. Nevertheless, it is important that members of the trade and the consuming public alike be aware that some gem materials could be affected by the procedure, and every effort should be made to ship such materials by methods that are not likely to be exposed to the sanitization process.
Note, too, that some of the color changes seen in our samples would not be permanent. Some of these colors will fade with exposure to light back to their original colors. Others can be changed back with heat. Still others will never revert to their original color. (For more on the color stability of irradiated gems, see K. Nassau, Gemstone Enhancement, 2nd ed., Butterworth-Heinemann, Oxford, 1994.)
Also as mentioned above, not all members of the same species or even the same variety will react similarly. For example, according to Dr. George Rossman of the California Institute of Technology, it is less likely that blue sapphires from basaltic deposits such as Thailand or Australia will change.
We recognize that other gem species or varieties, including ruby and emerald, may be affected to lesser degrees by this radiation dosage. In the second phase of our testing, which is already underway, we hope to answer this and many more questions about this newest concern to the industry.
For background information on commercial irradiation of gem materials, see
C. E. Ashbaugh, "Gemstone Irradiation and Radioactivity," Gems & Gemology, Winter 1988, pp. 196-213. For more on the possible effects of postal sanitization on gem materials, see the upcoming Winter 2001 issue of Gems & Gemology.
Here is the link I found this at
http://www.diamondtalk.com/forums/showthread.php?t=11358&highlight=US+postal+scanning
According to forum replies it appears it is not much of a hazard to the stones.
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