He spent 10 years creating a fragrance based on the legend of the Hope Diamond and his great grandmother Evalyn Walsh McLean, who previously owned the diamond.
Fable came out on the market in 1999 and is being sold at such stores as Bergdorf Goodman, Neiman Marcus and Von Maur.
Gregory, president of [Fable Fragrance], will make an appearance at Saturday's grand opening of the new Von Maur store in Charlestowne Mall, 3800 E. Main St., St. Charles.
He will be at the store from noon to 4 p.m. Along with explaining to people the history behind the fragrance, Gregory will bring with him the only known replica of the Hope Diamond in necklace form, along with his great grandmother's journals, dresses and china.
Gregory is donating 5 percent of Fable's sales nationally ' from now through the Christmas season ' to the American Red Cross and its relief efforts in New York City and Washington.
His great grandmother was a staunch supporter and volunteer for the American Red Cross.
'With this horrible tragedy that has occurred, I felt it was only appropriate to help however I could,' Gregory said. 'My CEO and I decided to continue where my great grandmother left off, supporting the American Red Cross.'
McLean also used the Hope Diamond to raise money for various charities.
'She would loan it out,' Gregory said. 'She used the Hope Diamond as the stage of her life to help bring something good to people.'
And he is hoping that through his Fable fragrance line, people learn more about his great grandmother.
'My great grandmother was a real person who touched real lives through a real object,' Gregory said.
The history of the Hope Diamond dates back to 1640, when the diamond most likely was discovered in the Kollur mine in Golconda, India.
Over the years, the diamond has been owned by Sultans, King Louis XIV of France and English royalty. McLean bought the diamond in 1911 for $180,000, and owned it until she died in 1947 of pneumonia. She was 60.
McLean was the last private owner of the diamond.
For all its glamour, the Hope Diamond is said to be cursed, bringing tragedy to all its owners.
McLean had her share of tragedy. Her first born child was killed in an automobile accident when he was 9, and her husband, Ed, died in a mental hospital.
But McLean bought the diamond despite the curse. She had said 'bad luck objects for me are lucky,' Gregory said. 'She turned around the curse, and used the diamond to raise money for various charities.'
And she was always upbeat.
'Whenever she left somewhere, she would never say good-bye, she would always say, 'I will see you later, and remember, there is a little hope in all of us,' '' Gregory said.