Princess

Both are square-ish, but cuts and eras differ. The princess (introduced in the 1960s) is a modern brilliant cut with sharp 90-degree corners and 50-58 triangular facets engineered for sparkle, like a square version of the round brilliant. The cushion (introduced in the 18th century) has rounded corners and larger, softer facets producing a more diffused, antique-feeling light return. Princess reads modern; cushion reads vintage.