cambridgefamily:

The engagement ring consists of 14 solitaire diamonds surrounding a 12-carat oval blue Ceylon sapphire set in 18-karat white gold. It was created by jeweler Garrard and cost at the time, 28,000 pounds sterling. Diana’s selection of this ring was unusual. It was neither custom-made nor unique and was, at the time of her engagement to Charles, featured in Garrard’s jewelry collection and available to anyone for purchase.