Then, this weekend, a ring from Alex Rodriguez (along with an Instagram engagement announcement with the simple caption "she said yes") may have launched a new craze for emerald-cut diamonds.

Since marrying David Beckham in 1999, Victoria Beckham has debuted a number of new engagement rings. From her marquise-cut ...

You can find high-quality, affordable engagement rings at a variety of retailers. Find the best prices at Blue Nile, ...

More recently, she's been spotted wearing a square-cut yellow diamond set on a pavé band. Another standout ring is the 15-carat, emerald-cut diamond Beckham received in 2008.

In August of 1985, Schwarzenegger proposed to Shriver with an emerald-cut diamond engagement ring, and less than a year later, the two married in Hyannis, Massachusetts.

It fetched $3.6 million, more than three-and-a-half times its high estimate. The ring features a 21.86-carat Colombian square-emerald-cut emerald flanked by diamonds and mounted on 18k yellow gold.