Common types of fancy-cut diamonds include oval, heart, princess, pear, emerald, marquise, and radiant cuts.
For oval diamonds, a length-to-width ratio of 1.5:1 is considered the "golden ratio"; they appear 15%–20% larger than round diamonds of the same carat weight, though one must check for the "bow-tie effect". Heart-shaped diamonds typically have a length-to-width ratio of approximately 1:1, offering a broad, full appearance. Princess-cut diamonds feature a square shape with sharp corners; they look 10%–15% larger than round diamonds of the same carat weight, and their crown facets allow for greater light entry. Pear-shaped diamonds (or teardrop cuts) ideally have a length-to-width ratio of 1.50–1.75; their shape-rounded at one end and pointed at the other-helps elongate the appearance of the hand. Emerald-cut diamonds utilize a step-cut style that offers exceptional clarity and transparency, requiring high-quality material; the classic length-to-width ratio ranges from 1.30 to 1.40. Marquise-cut diamonds usually have a length-to-width ratio of 1.75–2.55, and their elongated shape helps lengthen the look of the fingers. Radiant-cut diamonds feature numerous facets, creating a "fire" effect that can radiate outward in concentric circles.
