RFID Helps Gem Dealers Track the Diamonds They Buy, Cut and Sell

"The diamonds move faster than you can scan them," Gruen says. "It's simply impossible to scan the bar code every time they move. For that reason, it was not possible to know where things were—you just couldn't keep track."

As a result, says Gruen, the store had twice as much inventory on site as it needed because staff simply didn't know what they did and did not have in stock. Stones were regularly "lost"—that is, somewhere on the premises but missing from the inventory record—and, thus, inaccessible when needed.

With the PJM system, Gruen explains, Favorite Diamond uses RFID to complement the bar-code system. The jeweler's staff still applies bar codes to each diamond, but now they also attach an RFID tag, using a desktop interrogator to scan the bar code and capture the unique RFID number. The RFID and bar-code readings are transmitted to Favorite Diamond's management system to be linked to details about each stone, keyed in by Favorite Diamond employees.

PJM's StackTag labels are read-write capable, able to hold up to 8,000 bits of data, but Favorite Diamonds does not use them for that purpose. Instead, the diamond company utilizes the ID number only, storing all other data on the back-end system. The company also continues to use bar codes so staff can scan the bar-code number in those sections of the store that lack RFID readers. "They only have about 10 readers," Gruen says, "They don't have one at every station."

The real advantage to the RFID system, says Gruen, comes when boxes of diamonds are being moved. At this time, a box may hold 100 envelopes or more, each containing its own diamond. To scan a bar code for each when the entire box is moved would be impractical. In this case, the staff places the box in the Magellan RFID tunnel reader, which is about the size of a shoebox and can interrogate tags at a rate of 1,000 per second. Magellan provides the readers, RFID labels and application software.

"Now there is no such thing as moving a stone without logging that data," Gruen states. Laing says Favorite Diamond first approached Magellan for this solution in 2000, noting that, "We showed them the prototype in 2002." About a year later, he says, Favorite Diamond began using the system.