5.09 Ct. White Cabochon Quartz from Madagascar

This single specimen is a transparent white quartz, weighing 5.09 carats, presented in a cushion shape with dimensions of 10.01 x 9.18 x 6.60 mm. The gem has been fashioned as a cabochon, resulting in a smooth domed profile that emphasizes internal clarity and surface reflections. Clarity is graded as very slightly included when evaluated at eye level, which indicates only minor internal features that do not detract from overall transparency or visual appeal. The color intensity is colorless, and the surface polish is excellent, producing crisp surface reflections and a glasslike luster. There has been no enhancement applied to this material, and its documented origin is Madagascar, a source known for producing high quality quartz specimens with consistent transparency and clean crystal habits. The cabochon form moderates the appearance of brilliance in favor of a uniform, luminous glow that suits both minimalist and classic jewelry designs.

Optically this white quartz displays the characteristic vitreous luster and moderate light return typical of quartz family materials. Quartz has a refractive index of approximately 1.544 to 1.553, which yields a softer, more subdued brilliance than higher index gemstones. As a cabochon, the stone does not exhibit the faceted flashes of scintillation associated with brilliant cuts, instead offering broad, even reflections and an internal glow that accentuates the stone body and any subtle inclusions. When compared to other transparent gemstones in its category, white quartz is less refractive than white topaz, which has a refractive index around 1.61 to 1.64, and less refractive than goshenite, the colorless variety of beryl, which sits near 1.57. Compared to colorless sapphire, with an index near 1.76, and diamond, with a markedly higher index of 2.417, quartz returns less intense contrast and fire. Dispersion values further underscore these differences, with quartz showing very low dispersion, approximately 0.013, which produces minimal spectral fire relative to diamond or even sapphire. The result is an understated, elegant light behavior, favoring clarity and a steady, mirrorlike surface sheen rather than pronounced sparkle.

This piece is well suited to settings that take advantage of its cabochon silhouette and natural transparency, such as bezel mountings that protect the dome and allow the stone to read as a luminous focal point, or open gallery settings that permit viewing from multiple angles. The excellent polish amplifies surface reflections, making the stone appear larger and cleaner to the eye, while the very slight inclusions provide natural character without compromising visual purity. For designers and collectors seeking a natural, unenhanced Madagascar quartz with reliable optical behavior and a refined, subdued reflective quality, this example offers a dependable option. The Natural Gemstone Company presents this gem with full disclosure of treatment status and origin, and with an emphasis on material integrity and suitability for both bespoke and classic jewelry applications.