12.23 Ct. Cabochon Tourmaline from Madagascar

One translucent brown tourmaline weighing 12.23 carat is presented by The Natural Gemstone Company, round in outline with measured dimensions of 15.21 by 14.14 by 7.05 millimeters, cabochon cut, clarity grade slightly included at eye level, intense color intensity, and excellent polish, origin Madagascar, no enhancement. The overall mass and measured dimensions place this specimen in a size class that is substantial for cabochon work, and the round shape has been maintained with careful symmetry to maximize material yield from the rough. The cabochon profile exhibits a classic domed crown with a smooth convex surface and a well controlled base curvature. The height of the dome relative to the average diameter is approximately 48 percent, a proportion that contributes to a strong internal glow and effective light transmission for a translucent brown material, while also providing a robust profile for bezel and closed back settings in high end jewelry.

The cutting and finishing of this tourmaline demonstrate disciplined lapidary technique optimized for color and translucency rather than faceted brilliance. The absence of faceting shifts focus to the surface geometry and polish, and the lapidary workflow likely included controlled preforming to preserve color zoning, progressive grinding on diamond laps to refine the dome, and a multi stage polishing sequence using progressively finer abrasives. The final polish achieved is excellent, producing mirror like reflections and a smooth tactile surface, which indicates precise hand work or high quality machine finishing with diamond and cerium oxide or tin oxide polishing agents. Orientation of the cabochon was selected to present the most uniform color plane to the viewer, taking into account the pleochroic tendencies common to tourmaline. The cutter also balanced dome height and base flatness in order to leave sufficient thickness for secure setting and to reduce the risk of nicks along the perimeter, while maintaining a visually pleasing silhouette and live surface that responds to ambient light.

From a gemological perspective this brown tourmaline exhibits intense color intensity with warm to neutral brown tone and rich chestnut overtones under standard daylight equivalent illumination, characteristics that appeal to collectors who favor deep natural hues. Being translucent rather than opaque, the material displays internal color transmission and a soft inner glow rather than facet derived scintillation, which is attractive for designs that emphasize depth of color and a velvety visual texture. The clarity grade slightly included evaluated at eye level denotes the presence of internal features that are observable without magnification, yet the inclusions do not overly compromise the structural integrity or the overall visual appeal. Typical physical properties of tourmaline such as a refractive index range around 1.624 to 1.644 and a specific gravity near 3.06, together with a Mohs hardness approximately 7 to 7.5, inform handling and setting recommendations, while the lack of enhancement confirms the stone is in its natural state, preferred by discerning buyers and appraisal laboratories.

This Madagascar origin specimen is an excellent choice for bespoke jewelry and for collectors seeking naturally colored cabochon tourmaline with substantial weight and refined finishing. The stone is well suited for a variety of settings including bezel mountings, closed back settings in pendants, and substantial rings where the dome can be shown to advantage, and the preserved thickness allows secure bezel construction without compromising the visual plane. Care recommendations include avoiding ultrasonic cleaning if significant internal inclusions are present, avoiding harsh chemicals and extreme thermal shock, and routine gentle cleaning with warm soapy water and a soft brush. The Natural Gemstone Company stands behind the provenance and the stated parameters of this tourmaline, and we are prepared to provide additional gemological documentation and high resolution images upon request, as well as bespoke mounting and design consultation for clients who wish to incorporate this intense brown cabochon into a finished and enduring piece.