Complex sentence: The diamond was originally owned by Harriet Annenberg Ames and was subsequently purchased at auction by Robert Kenmore, owner of the luxury brand Cartier, for a then record $1,050,000.
Split into simpler sentences: The diamond was originally owned by Harriet Annenberg Ames. It was subsequently purchased at auction by Robert Kenmore, owner of the luxury brand Cartier, for a then record $1,050,000.