The model, 29, told Us Weekly "it feels so great" to be wearing the three-stone bauble. "It's a rose cut. It's a beautiful ring."
Alves also admitted she hasn't done much wedding planning since McConaughey, 42, proposed on Christmas morning -- mostly because she's been working on her Muxo handbag line. See more pictures of Camila's ring.
"It's amazing to be designing. We've been with QVC for a little bit over a year and we have a couture line," she told Us. "It's at Nordstrom and other department stores, but with QVC it's special, because it's instant gratification of hearing from the customer."
Alves and McConaughey met at an L.A. bar in 2006 and have two children together: son Levi, 3, and daughter, Vida, 2.