21.43 Ct. Cabochon Malachite from Russia

This oval shaped malachite weighs 21.43 carats, and its dimensions measure 18.14 x 13.32 x 8.62 mm, the profile exhibits a high domed cabochon with a carefully controlled curvature that optimizes surface reflection and band pattern visibility. The material is opaque as expected for gem quality malachite, and the color presents a vivid intensity that ranges from deep forest green to lighter grassy zones, the color saturation is uniform across the visible surface with pronounced concentric and linear banding that is characteristic of well formed malachite from Russian deposits. Clarity is graded as eye clean when evaluated at normal viewing distance, there are no perceptible fractures or destabilizing voids visible to the naked eye, and the absence of secondary treatments or stabilization is confirmed, the piece is natural with no enhancement. The cut is a classic cabochon, executed to emphasize the layering, the oval outline is well centered, and the girdle is even which facilitates predictable setting margins for jewellery fabrication.

The lapidary techniques applied to this specimen focus on preserving the stratigraphy of the banding while producing an excellent polish, the initial preform was oriented to accentuate the concentric growth rings, and shaping was completed on progressively finer diamond laps to maintain geometry without inducing micro fractures. Final grinding and smoothing utilized progressively finer abrasives to remove any wheel marks, and the polish was achieved with fine polishing compounds on a soft lap to produce a mirror like finish that highlights the contrast between velvety deep zones and brighter band interfaces. Attention to dome symmetry and apex alignment was prioritized to ensure optical balance when viewed from multiple angles, the dome height of 8.62 mm is proportioned to the plan dimensions to create a pleasing silhouette and to distribute surface curvature evenly across the stone. The cabochon surfaces display minimal undulations, the polish exhibits strong specular reflection, and the band transitions remain crisp which is indicative of controlled material removal and careful hand finishing rather than aggressive tumbling.

From a technical use and conservation perspective this malachite is best suited to bezel type settings or low profile closed back mountings that protect the girdle and prevent edge chipping, the relatively low Mohs hardness of malachite necessitates protective design choices for rings and bracelets that will see frequent wear, pendants and brooches are highly suitable for showcasing the concentric bullseye banding while reducing mechanical risk. Cleaning should be restricted to soft brushes and mild soapy water, avoid abrasive cleaners, acidic solutions, ultrasonic and steam cleaning processes, sudden temperature changes and exposure to household chemicals can alter surface luster and in some cases etch the carbonate mineral matrix. Provenance for this piece is Russia, and the geological origin contributes to the specific banding morphology and deep green palette, specimens from this source are valued for their dense banding and consistent color saturation. This description and assessment are supplied by The Natural Gemstone Company, and our lapidary team stands ready to advise on custom mounting approaches and conservation practices tailored to this 21.43 carat green malachite cabochon.