Modern 18k Rose Gold 1 Carat Total Weight Approximately. The weight of center stone approximately .75 of a carat. Diamond Engagement Ring– A fabulous diamond right hand ring or engagement ring. The center stone is bezel set and approximately .75 carat diamond with a halo of 21 smaller diamonds surrounding the central stone and 5 diamonds on each shoulder of the ring. Approximately 4.7 grams inclusive and a size 6.5.