It's been one week since Zoë Kravitz debuted an unmissable diamond ring on that finger. The gravitational pull of the crater-sized gemstone kept her rumored fiancé, Harry Styles , in orbit on April 19. Three off-duty outfits and one People confirmation later, Kravitz's solo April 27 stroll gave the paparazzi a proper close-up of the engagement ring. The newly-engaged actor couldn't have set up a better canvas to spotlight her new sparkler. She kept it casual in a heather gray long-sleeve, black trousers, and the high-vamp flats trend, before the bezel-set diamond stole the show. Her outfit's two additional rings—a slim, stone-free band and a coiled, snake-shaped style—hailed from Jessica McCormack , Kravitz's favorite jeweler. Confirmation of her engagement ring's designer, on the other hand, is still under wraps. Even without the brand name locked in, engagement ring experts estimate it's between six and seven figures.…