A 1-carat diamond solitaire engagement ring is a perfect option to propose with. It's one of the most popular sizes of a diamond in a ring in the United States. However, this varies by region and demographics. A 1 ct diamond solitaire engagement ring balances between luxury and elegance and remains a timeless choice for proposals. Whether in yellow, white, or rose gold, these solitaire engagement rings steal hearts with their elegant opulence.