15.22 Ct. Cabochon Tanzanite from Tanzania

This specimen is a translucent, round shape violet tanzanite weighing 15.22 carats, with precise dimensions of 14.55 x 14.82 x 8.51 mm. The cutter opted for a cabochon finish rather than a faceted pavilion and crown, producing a smooth domed profile that emphasizes color depth and internal texture. The round outline is effectively centered, with the minor difference between the two measured diameters indicating a very slight natural asymmetry that was retained to maximize yield and color uniformity. The cabochon geometry has been controlled to deliver a balanced dome height relative to the diameter, allowing light to travel through the stone and to interact with internal zoning and inclusions, while the excellent polish produces a satiny to vitreous surface luster across the entire dome. The Natural Gemstone Company presents this piece as a collector grade cabochon that combines significant carat weight with careful material preservation during preforming and final shaping.

Optically the tanzanite displays vivid color intensity, with a strong violet dominance that benefits from the cabochon cut and the documented heat treatment. Heat treatment is the established enhancement for zoisite to preferentially stabilize blue and violet hues by reducing brownish absorption bands and by altering trace vanadium valence states, and this sample conforms to that standard practice. Pleochroism in tanzanite is a key optical characteristic, and although cabochon cuts do not present angular facets to separate pleochroic directions, the domed profile preserves the directional color effects as zones of deeper saturation when viewed from differing angles. Clarity is graded included at eye level, which indicates that under normal observation naked eye inclusions are visible, these may present as needles, fine planar growth features, and localized clouding. In this cabochon configuration those inclusions contribute to internal depth and a subtle shimmer rather than detracting from the gem as a faceted stone might, and the translucency allows internal textures to be appreciated as part of the stone character.

From a workmanship perspective the cutting and polishing strategy is oriented toward maximizing apparent color saturation while maintaining structural integrity. The cutter chose to retain a robust thickness, reflected in the 8.51 mm depth, to preserve strong color transmission and to prevent common cleavage related damage that can occur during aggressive thinning. The rounding and smoothing of the girdle edge are executed to facilitate secure bezel mounting, and the dome profile is proportioned to avoid optical flat spots that would reduce the perceived saturation. The excellent polish indicates thorough final laps and fine abrasive sequences, producing minimal surface microabrasion and ensuring that the surface reflects light evenly. Provenance is Tanzania, the primary known source for tanzanite, and this origin informs the material character. The Merelani mining region and surrounding strata have given rise to the modern history of tanzanite, and although the gem family is geologically recent in gem market terms, it carries a contemporary heritage linking artisanal mining practices to modern lapidary refinement.

Historically and culturally, tanzanite occupies a role analogous to long established violet and blue gemstones such as amethyst and sapphire, which have been used in ceremonial and royal jewelry across many cultures. While tanzanite as a named gem entered gemological consciousness in the late twentieth century, the visual language it shares with violet and blue stones invites traditional applications, including use in signet and devotional gems, in rings intended as birthstone symbols, and in talismanic jewelry where saturated color was historically associated with status and spiritual clarity. In modern practice tanzanite is frequently chosen as an alternative to classic blue stones, offering a distinctive violet nuance preferred by collectors and designers seeking a specific chromatic palette. The Natural Gemstone Company sources material mindful of these traditions, and this cabochon is well suited to pieces that reference historical jewelry paradigms while remaining contemporary in execution.

For setting, wear, and care the technical considerations derive from the material properties and the cabochon form. Tanzanite has a Mohs hardness around 6.5 to 7, and the stone must be protected from abrasion, sharp blows, and extreme thermal shocks. The substantial thickness of this cabochon provides good resistance to impact, but a bezel setting is recommended as the most protective and stable mounting for daily wear, the bezel also secures the dome and reduces the risk of chipping at the edge. Open back settings can enhance light transmission for greater perceived brightness, but for this included and translucent cabochon a closed back or partial backing will minimize exposure to oils and chemicals that could temporarily alter surface appearance. Heat treatment is stable under normal conditions, however avoid exposure to uncontrolled household heat sources and strong acids. Ultrasonic cleaning can be considered with caution and only after consultation with a qualified gem handler, because existing internal inclusions can sometimes propagate fractures under ultrasonic stress.

This tanzanite cabochon is presented by The Natural Gemstone Company with full disclosure of enhancement and origin, and it is ideal for collectors, period inspired jewelry designers, and connoisseurs who value both optical depth and historical resonance. The combination of 15.22 carats, near round dimensions, vivid violet color, controlled cabochon geometry, included clarity at eye level, and excellent polish makes this piece a noteworthy example of contemporary lapidary practice applied to East African material. For custom mounting, certification options, or further technical images and lighting studies to assess pleochroic behavior under different viewing axes, The Natural Gemstone Company can provide additional support and documentation tailored to professional requirements.