Noonans Mayfair The ring features a principal cabochon stone, or a rounded, polished center gem. In this case, the center stone is a sapphire, and it’s surrounded by two emeralds and two stones ...

In years past, Kate Middleton’s famous sapphire and diamond engagement ring—the same ring once worn by her mother-in-law, Princess Diana—used to be a firm staple in her wardrobe. After her ...