T he Okavango Blue Diamond, a dazzling 20.46-carat stone, is more than just a beautiful jewel-it's practically a miracle of nature. Unearthed from the Orapa mine in Botswana, this rare gem has ...

"The diamonds can range from clear to very deep blue," Martoia said. "The more boron, the deeper the blue." She added that it's impossible to predict the exact color a memorial diamond will take on.

The cushion-shaped brilliant-cut blue diamond with VVS1 clarity is mounted ... cut diamond pendants of 10.10 and 10.08 carats, each D-color and flawless. The earrings fetched more than $1.8 ...