84.77 Ct. Cabochon Moonstone from Ceylon (Sri Lanka)

This offering from The Natural Gemstone Company is an exceptional example of a classic cabochon moonstone, presented as a single opaque grey specimen weighing 84.77 carats, with exact dimensions 29.39 x 26.36 x 15.51 mm, oval outline, and natural origin Ceylon Sri Lanka, no enhancement. The reported clarity is very slightly included, evaluated at eye level, which in practical terms means that the stone exhibits only minimal internal features that are visible to a trained observer without magnification, while remaining visually clean to most viewers. The medium intense body color is an even, cool grey, and the cabochon form emphasizes the subsurface optical phenomena that define moonstone, while the excellent polish produces crisp reflections of incident light across the dome. The weight to size relationship is consistent with a dense feldspar matrix, and the overall presentation is of a gem that has been cut and finished with attention to preserving mass and achieving an optimal dome profile.

The cut is a high dome cabochon, with a height to length ratio implied by the measurements that produces a pronounced curved profile, ideal for maximizing adularescence produced by submicroscopic lamellar intergrowths within the orthoclase and albite layering. Because this moonstone is opaque, the optical effect is presented as a soft sheen rather than a sharp band of light, and the medium intense body color moderates the contrast of the sheen so that it reads as a refined, grey silver glow across the dome. The absence of faceting directs all light modulation to surface curvature and internal scattering, and the cutter has maintained excellent symmetry along the oval axis, the length to width ratio being near equant which produces a balanced visual footprint for pendants and brooches. The excellent polish is evident in the specular highlights visible on the crown, indicating that the lapidary achieved a very smooth, low microtopography finish, which is critical for cabochons because surface roughness can disrupt the apparent quality of adularescence.

Clarity assessment as very slightly included at eye level indicates inclusions that are typically limited to fine cleavage planes, minute two phase or solid inclusions, or localized growth lineations common to feldspathic gem materials, and these do not substantially interfere with stability or optical performance. From a gemological handling standpoint, the cabochon geometry and inclusion profile suggest good durability for everyday jewelry when set appropriately, though care should be taken during setting to avoid high point pressure on the dome or exposure to sharp blows. For mounting, a full bezel setting is recommended to secure the high dome and to protect the girdle area, while a partial bezel or custom cup setting can be designed to maximize visible surface area if preferred. The dimensions and weight make this stone particularly suitable for prominent pendants, signet style rings with protective bezels, or bespoke brooches where the mass and presence of an 84.77 carat cabochon are desired.

Provenance and treatment status are central to accurate valuation, and this moonstone is reported as untreated, with origin Ceylon Sri Lanka, which is consistent with a historical source known for producing fine feldspar specimens. The Natural Gemstone Company can provide documentation of origin upon request, and our quality control protocols include visual microscopy, polished surface examination, and comparative observation under standard lighting to confirm the absence of dye, coating, or other enhancements. For care, cleaning with warm water, a mild detergent, and a soft cloth is recommended, avoiding aggressive ultrasonic cleaners and steam that can exacerbate cleavage or propagate microfractures in feldspar group minerals. When designing settings, consider metal seat geometries that accommodate the 15.51 mm dome height, leaving adequate clearance while providing protective edges, and orient the oval axis so that the adularescent sheen is presented in the most flattering direction relative to the intended mounting. For collectors and designers seeking a substantial, naturally untreated cabochon, this grey moonstone from The Natural Gemstone Company represents a technically refined example with measurement precision, excellent surface finish, and provenance aligned with traditional feldspar sourcing.