31.61 Ct. Brown Cabochon Moonstone from Ceylon (Sri Lanka)

This listing presents one translucent brown moonstone from Ceylon, offered by The Natural Gemstone Company, weighing 31.61 carats, with an oval outline measuring 20.97 by 14.75 by 13.64 millimeters. The specimen is fashioned as a traditional cabochon, with a smoothly domed crown and a carefully contoured pavilion, chosen to enhance the internal light scattering that defines moonstone adularescence. The oval proportions are well balanced, enabling even light return across the long axis, while the substantial depth of 13.64 millimeters contributes to a pleasing three dimensional presence when set. Color is described as medium intensity brown, presented in a translucent body that permits soft internal glow without becoming opaque, allowing both the body color and the subtle internal sheen to register effectively in natural and diffused light. Weight to size ratio aligns with expectations for a dense feldspar cabochon of this scale, offering a tactile sense of substance and presence suitable for statement pieces.

Clarity is graded as very slightly included, evaluated at eye level, a practical designation that indicates small internal features are present but do not detract from overall visual appeal under normal viewing conditions. In this example inclusions are fine and sparse, consistent with natural growth features in orthoclase type feldspar, and are accommodated within the design of the cabochon so that adularescent effects remain uncompromised. The cut is a full, high dome cabochon, executed to maximize the planar lamellar interference that produces the moonstone sheen, with symmetry maintained across the transverse and longitudinal axes to prevent directional color shifts when the stone is rotated. Surface finish is excellent polish, achieved by progressive preform shaping, sequential sanding through fine grits, and final buffing with cerium oxide, resulting in a high luster surface that promotes optimal light transmission and tangential reflection. There has been no enhancement applied to this stone, a natural, untreated example of Ceylon material, free from dyes, oiling, heating, or coating, attributes that are significant to collectors and connoisseurs who prioritize untreated gems.

For mounting and care, consider settings that protect the domed surface and display the oval orientation to accentuate the adularescence, because the optical phenomenon is directional and is best viewed along the dome plane. A low to moderate bezel setting offers excellent protection for the cabochon rim and reduces the risk of abrasion, while an open back or partial gallery can allow light to penetrate, enhancing internal glow, though care should be taken to support the stone without exposing it to shock. Moonstone has a Mohs hardness in the range of 6 to 6.5, and exhibits cleavage tendencies associated with the feldspar group, therefore mechanical protection is recommended for rings intended for daily wear, pendants and brooches are excellent alternatives for larger stones. Cleaning should be by warm soapy water and a soft brush, ultrasonic and steam cleaners are not recommended for stones with internal inclusions or cleavage planes. The provenance from Ceylon contributes to both aesthetic and market desirability, reflecting a long established source of high quality feldspar material. If you require additional information on setting dimensions, matching pairs, or certification options, The Natural Gemstone Company can provide further technical data and photographs under controlled lighting to assist in design planning.