South Sea cultured pearls come from warm tropical seas where the large Pinctada maxima oysters thrive, allowing the production of the biggest cultured pearls. The primary producing regions are Australia, the Philippines, and Indonesia. Indonesia completes the trio because its extensive warm coastal waters host many Pinctada maxima farms, yielding the large, lustrous pearls that define the South Sea category. Other options fit different pearl types: Japan is famous for Akoya pearls from a smaller oyster, while India and Vietnam are not major suppliers of South Sea pearls.

In gem cutting, a free-form shape that mixes flat facets with curved surfaces is described as a fantasy cut. This label signals an imaginative, nonstandard design created to achieve a unique silhouette and light reflection, combining precise flat facets for sparkle with curved areas that bend light in distinctive ways. It’s the opposite of regular, textbook shapes, which is why it suits an unusual, artistic form. The other terms describe more traditional styles. A briolette is a bead-like cut with many facets all around the surface, typically uniform and fully faceted rather than free-form. A table cut centers on a very flat top with minimal additional shaping, emphasizing flat surfaces. Crown cut isn’t a standard term for this concept and doesn’t convey the same free-form, mixed-surface idea.

Heat treatments are commonly used on rubies to enhance color and clarity. Controlled heating can melt away or reduce brownish or grayish tones and deepen the red, yielding a more vibrant, desirable hue and often better transparency. Because this treatment can significantly affect a stone’s value and appearance, disclosure is standard in grading reports and in the jewelry market. While other gemstones may receive different treatments—emeralds are typically oil-treated to improve fracture visibility, and opals have their own set of considerations—heat treatment remains the example most consistently associated with explicit disclosure, making ruby the best answer.

Table width, expressed as a percentage of the diamond’s diameter, is a key factor in how light travels inside a round brilliant. If the table is too wide, more light escapes upward, reducing light return and making the gem appear less brilliant and lively. If the table is too narrow, light entry is restricted and some facets can darken, also dulling overall brightness. The commonly cited ideal range, about 53% to 57%, strikes a balance: it gives a pleasing face-up view while allowing enough interaction of light with the crown and pavilion facets to maximize brilliance and fire. In practice, you’ll see many well-cut rounds with tables in this middle band, producing strong light performance without the trade-offs that come with tables that are too large or too small.