4.28 Ct. Yellowish Green Prasiolite from Madagascar

This prasiolite offered by The Natural Gemstone Company is a transparent, yellowish green specimen weighing 4.28 carats, cut to an emerald cut shape with precise dimensions of 10.99 x 9.35 x 5.74 mm. The gem presents a medium color intensity, with a calibrated clarity grade of very slightly included evaluated at eye level, and an excellent polish applied to all facet junctions. The material is heat treated to produce and stabilize its green tone, and it is sourced from Madagascar, a locality known for producing clean quartz material with consistent hue tone. The combination of weight and planar dimensions results in a substantial face up area that emphasizes color and step cut reflections, making this prasiolite a strong candidate for statement rings and bespoke pieces where table size and color presence are priorities.

The emerald cut employed here is a classic step cut, featuring broad, parallel crown and pavilion facets that emphasize color saturation and internal clarity rather than dispersion based flash. Proportions yield a depth that measures approximately 56 percent relative to the average of the length and width, a proportion that balances face up spread with appropriate pavilion depth for controlled light return. The step facet architecture produces large, mirror like facet planes that deliver broad flashes and well defined light and dark patterning, rather than scintillation typical of brilliant cuts. The very slightly included clarity at eye level indicates minor pinpoint or negligible feathering confined to lower pavilion regions that do not interrupt the table window or compromise structural integrity. The excellent polish ensures minimal surface diffusion, optimizing surface luster and allowing the inherent refractive properties of quartz to dominate light behavior. As a quartz species prasiolite displays a refractive index range approximately 1.544 to 1.553, modest birefringence near 0.009, and low dispersion around 0.013, which informs expectations for brilliance and fire.

Optical behavior across lighting environments follows predictably from the combination of step cut geometry and quartz optical constants. In cool daylight with a balanced spectral distribution the stone reads as a clear yellowish green, with the medium intensity producing uniform color across the table and step facets, and with crisp, linear flashes along the facet edges. Under warm incandescent illumination the yellow component becomes more pronounced producing a warmer, more yellow leaning green, as the human eye and the gem both respond to the longer wavelengths in the light source. Under modern cool white LED display lighting the stone tends toward the greener side of its range, with pronounced contrast between bright facet planes and deeper step shadows, making the step cut pattern more architecturally visible. In direct, focused lighting such as a spotlight or jewelry display lamp the emerald cut produces large, controlled flashes and high contrast facet reflections, while the inherently low dispersion of quartz precludes strong spectral fire. In soft, diffuse ambient light the medium intensity appears more subtle and evenly distributed, reducing contrast but enhancing apparent clarity, which benefits the stone given its very slightly included grade. In wearable contexts movement produces linear flashes that travel along the step facets rather than rapid scintillation, a behavior prized by connoisseurs who value optical discipline and clarity.

From a practical and setting perspective this prasiolite benefits from designs that expose the pavilion to light while protecting the emerald cut corners from mechanical impact, prong settings with supportive corner claws or a four corner bezel with slight elevation are appropriate choices. Because the piece is heat treated it is dimensionally and chromatically stable under normal wear conditions, however prasiolite, as quartz, can be sensitive to extreme thermal shock and harsh chemicals so ordinary care is advised. Ultrasonic cleaning is generally acceptable for clean quartz material but should be evaluated once set and after consultation with your bench jeweler. The Natural Gemstone Company recommends settings that allow the table to face light sources to maximize the broad step reflections and color presence, and we are available to advise on mounting options and customization to showcase the unique balance of color, clarity, and architectural cut in this 4.28 carat Madagascar prasiolite.