12.01 Ct. Cabochon Amethyst from Brazil

This listing describes a single, translucent amethyst, weight 12.01 carats, fashioned to an oval outline with finished dimensions 18.14 by 13.22 by 7.14 millimeters. The piece is cut as a cabochon, presenting a domed profile rather than faceted planes, and exhibits vivid color intensity with an excellent polish. Clarity is noted as very slightly included when evaluated at eye level, and the material has been subjected to heat treatment to optimize color. Origin is Brazil, which is globally recognized for producing high quality amethyst material. The Natural Gemstone Company supplies this specimen as a lapidary-grade cabochon suitable for precision jewelry settings and collectors who prioritize color and uniformity of tone in non-faceted presentations.

From a cutting and finish perspective, this cabochon demonstrates deliberate control of dome geometry, symmetry, and surface finish. The dome height approximates the thickness indicated by the 7.14 millimeter depth, balanced to maintain a pleasing optical face while preserving enough depth to retain saturation without appearing overly dark in transmitted light. As a cabochon, the piece relies on convex curvature and polish to manage light return rather than faceting angles; the lapidary has employed progressive fine abrasives and a final rouge or cerium oxide polish to reach an excellent luster. The oval outline is well centered with even girdle proportions, minimizing edge thinning that could compromise setting security. No evidence of cabochon-specific phenomena such as chatoyancy or asterism is present, indicating that the internal structure and alignment of inclusions are such that the dome serves principally to enhance color saturation and translucency.

Optical and gemological properties are consistent with natural amethyst, with a refractive index in the expected range near 1.544 to 1.553 and a specific gravity around 2.65, factors that inform cutting resistance and setting considerations. The vivid purple hue of this specimen displays relatively uniform saturation across the table, with slight internal color zoning visible on close inspection, which is typical for natural Brazilian amethyst and contributes to its visual depth. Pleochroism in amethyst is generally weak, manifesting as variations between bluish-purple and reddish-purple tones when rotated under directional light, and this cabochon shows subtle tone shifts rather than strong dichroic effects, an outcome of careful orientation of the rough during preform stage to present the most desirable hue across the face. Heat treatment has been applied to stabilize and deepen the purple, a standard enhancement for amethyst that reduces brownish overtones and improves visual uniformity; such treatment is permanent under normal conditions and is disclosed here for full provenance transparency.

Clarity characteristics are described as very slightly included at the eye level, which in practical terms means the cabochon is essentially eye-clean from customary viewing distances, with minor internal features that do not materially detract from light transmission or structural integrity. These inclusions may manifest as fine needles, wisps, or tiny mineral crystals typical of natural quartz varieties, and they serve as identification markers of natural origin rather than detractors. For jewelry application, the cabochon shape and thickness recommend secure settings such as bezel or closed-back mounts that support the girdle and protect the dome; open-back settings may be used to enhance light ingress when mounted in a pendant or ring, but care should be taken to match the setting seat precisely to the 18.14 by 13.22 millimeter dimensions to avoid stress points. Given the Mohs hardness of approximately 7 for quartz, standard wear is appropriate but abrasive contact and high heat should be avoided despite prior heat treatment. The Natural Gemstone Company stands behind the lapidary quality and disclosure of treatment and origin, and we advise designers and clients to consider this cabochon for designs prioritizing saturated purple color, stable optical performance, and a classical oval cabochon aesthetic.