The 49-year-old performer was photographed rocking the massive bling on her way to the gym in Miami, Florida, on Wednesday, just days after she and Alex Rodriguez announced their engagement.
The couple, who had been dating for two years, took to Instagram to announce the happy news on Saturday; Rodriguez proposed on the pair's tropical vacation together.
Lopez flew solo for Wednesday's outing, however, looking fit in a black Guess T-shirt and black leggings. Her stunning new accessory -- which is valued at over $1 million -- was in full view as she headed to her workout.
"Jennifer was shocked as the two talked about marriage, but she wasn’t aware he’d be proposing that day," the source said. "Both Alex and Jennifer have been married before, and official wedding planning hasn’t started, but the two do want to celebrate the day with their family and famous friends."
The source added that J-Rod's wedding "will be nothing short of incredible." According to the source, their kids -- the World of Dance judge shares 11-year-old twins Emme and Max with her ex-husband, Marc Anthony, while Rodriguez has two daughters, Natasha, 14, and Ella, 10, with his ex-wife, Cynthia Scurtis -- were a "driving force" in their engagement.
"The couple loves to entertain and have fun, and their wedding will be nothing short of incredible," the source said. "Their kids will play a big part in their wedding, as they were a driving force in the proposal."