Stephen Connelly, director of Cleave and Company, told The Associated Press the intense media attention has been "a bit of a shock." He added: "We're not going to be making replicas of it. If you want a ring, then we'll design you a different one."
Harry has said he sourced a diamond from Botswana for the yellow gold engagement ring, which also features smaller diamonds that had belonged to his mother, Princess Diana, so she could be with them "on this crazy journey together."
David Thomas, a former Crown Jeweler who looked after the royal family's jewels and now works with Cleave and Company, said working on the ring was the "biggest and hardest secret" he's had to keep in his life.
He said he has been bombarded by questions from the press - including how much the ring had cost - but he declined to violate the royal couple's privacy.
"Jewelers are like doctors: we never discuss our patients!" Thomas said.
The company wanted to keep such a low profile that it only allowed the AP access to its workshop on the condition that its location is kept secret.
Harry and Markle are getting married at St. George's Chapel in Windsor Castle in May.
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