Emerald cut diamonds, and emerald cut diamond engagement rings, offer several unique characteristics:

1. Clarity: Due to their long shape and flat facets, emerald cut diamonds show inclusions and flaws more than most diamond shapes. For that reason, emerald cut diamonds generally have a much clarity, color, and cut to ensure a stunning high-quality stone.
2. Elegance: The elongated shape of the emerald cut diamond gives and elegant and sophisticated appearance. It's a classic cut often associated with vintage or art deco styles.
3. Size: The emerald cut diamond can appear larger than other shapes of exact carat weight due to its large surface areas and fewer facets.
4. Uniqueness: The emerald cut diamond offers a unique and distinctive look that's sure to make your engagement ring stand out!

The biggest differences between round and emerald cut diamond engagement rings are their shape and the way they reflect light.

1. Shape: The emerald cut diamond will offer an elongated look with truncated corners.
2. Appearance: While round diamonds are known for brilliant sparkle and fire, emerald cut diamond create a "hall of mirror" effect that emphasis clarity and depth rather than sparkle.
3. Cut: Emerald diamonds are cut differently than round diamonds, with more emphasis on clarity and depth.
4. Price: Emerald cut diamonds tend to be less expensive than round diamonds of similar size and quality.

Emerald cut diamond engagement rings are generally less expensive than their round diamond engagement ring counterparts, but are no less unique and stunning in appearance.