Between the diamond solitaire and three-stone “past, present, future” jewelry lies Jewelry.com's latest concept: Duo. The new collection of jewelry featuring two diamonds per piece was launched recently at a gala event held at the New York Public Library. Jewelry.com chairman Ofer Azrielant says two is the forgotten number when it comes to diamond jewelry. Virginia Halevi, the site's editor-in-chief, adds, “One is lonely, three's a crowd, but two is the true essence of romance.” The Duo collection is popularly priced. Pieces are 10k or 14k gold and retail for less than $1,000, with many priced under $500. It's targeted to celebrate any kind of love—romance between couples, the bond between parent and child, or closeness between friends. The collection is available online or through two of Jewelry.com's participating partner retailers, JC Penney and Zales.