Lifestyle Style Diamond Experts Weigh In on Jennifer Lopez's 'Extremely Rare' Green Diamond Engagement from Ben Affleck Two diamond experts talk to PEOPLE about the gem at the center of the star's engagement ring: "The rarity of a natural green diamond cannot be overstated" By Jackie Fields Jackie Fields Instagram Jackie Fields is the Deputy Beauty Director at PEOPLE. A Tufts University and Parsons School of Design alum, she joined the brand as an editorial assistant in 2005 and has previously held the titles of reporter, writer-reporter, writer, editor, and senior editor. In 2009, she reported the magazine's first BeautyWatch page. During the last 12 years, she has focused almost entirely on beauty – specifically celebrity and market trends. Jackie most enjoys heading up the brand's annual drugstore Beauty Awards. When she is not reporting, writing, and editing content, she is testing fragrances, lipsticks, and products for 4c hair or catering to her beloved English Bulldog, Bowie. People Editorial Guidelines Published on April 11, 2022 09:25PM EDT Share Tweet Pin Email Jennifer Lopez and Ben Affleck marked their engagement with a gorgeous token — a green diamond ring. The music icon once wrote in her On the JLo newsletter that the color is particularly symbolic. "I always say the color green is my lucky color," Lopez, 52, previously wrote. "I've realized there are many moments in my life where amazing things happened when I was wearing green." Two diamond experts talked to PEOPLE about the unique piece of jewelry's green diamond stone. "The rarity of a natural green diamond cannot be overstated," explains Grant Mobley, Diamond Expert at Natural Diamond Council. "Generally speaking, green is the second rarest natural color of a diamond with fancy red being the rarest. Only a small handful of green diamonds come to the market every year and almost never are they in the vivid color and size of this diamond." JLo; Steve Granitz/FilmMagic According to Andrew Brown, CEO of New York City-based luxury buying company WP Diamonds: "Green diamonds are indeed extremely rare. Not quite as rare as pink diamonds, but, the intense and vivid greens found to date have been smaller than pinks we have seen." Jennifer Lopez, Ben Affleck Kept Their Engagement 'Quiet for a Few Days' Before Telling Fans: Source While the exact shade of the sparkler isn't easy to see, Mobley guesses it's a fancy vivid green. "The exact color grading of the diamond has not been disclosed, but it is clear in the photos that it is exceptional and among the most rare." JLo Where would such a unique color diamond come from? For more on Jennifer Lopez and Ben Affleck's engagement, listen below to our daily podcast PEOPLE Every Day. Explains Mobley, "Green diamonds get their unique color from the exposure to natural radiation deep within the Earth after they have formed and this causes them to reflect green light. It is very rare for this to penetrate through the entire rough diamond and therefore is usually just a thin layer on the surface of the rough diamond. This fact makes green diamonds among the most difficult to cut and a diamond like this could have taken a year or more to plan and cut to ensure that it reflects the best cut and color possible. Jennifer Lopez and Ben Affleck 'Are Not Talking' About Wedding Planning After Announcing Engagement: Source Ben Affleck and Jennifer Lopez. Arturo Holmes/Getty If pure, Mobley says, "you can expect the value of this green diamond to significantly increase over time. Decades of price data show that all natural diamonds gradually increase in value over time and natural fancy color diamonds increase significantly faster and are therefore a very solid investment. And both pros agree, this rare gemstone is an "incredible" sight in real life. PEOPLE confirmed through Lopez's rep on Friday that she and Affleck, 49, are engaged. Lopez had been photographed days earlier wearing what appeared to be her engagement ring on her finger. On Friday, her sister Lynda shared a photo of the ring to her Instagram Story while sending congratulations to the pair. lyndalopez08/Instagram Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. The couple's exciting news comes a year after they rekindled their romance. In February, Lopez told PEOPLE what makes their connection different now compared to 18 years ago, saying, "We're older now, we're smarter, we have more experience, we're at different places in our lives, we have kids now, and we have to be very conscious of those things." The Marry Me star shares 14-year-old twins Emme and Max with ex-husband Marc Anthony, and Affleck, 49, shares three kids with ex-wife Jennifer Garner: Violet, 16, Seraphina, 13, and Samuel, 10.