**Complimentary Specimens** As a gesture of appreciation, winning lots with a final hammer price above €50 will include one small additional mineral offered entirely free of charge. —————— Description: At first glance, these crystals may easily be mistaken for emeralds. The colour is unmistakably green, intensely saturated and alive, with a luminosity that immediately evokes fine gem material. Yet this first impression barely scratches the surface of what this specimen truly represents. Beyond the familiar association with emerald green, this piece belongs to a far rarer and more storied mineral lineage, one that transcends conventional gemstone comparison. This is dioptase from Tsumeb, Namibia, a locality regarded as the absolute reference for this mineral worldwide. The crystals rise sharply from the matrix, fully terminated and exceptionally well formed, displaying a geometric precision that feels almost deliberate. Each crystal reflects light with a vitreous clarity that enhances the depth of colour, revealing an emerald green so pure and concentrated that it rivals, and in many cases surpasses, the visual authority of traditional emerald gemstones. The dioptase presents itself here not as fragile microcrystals, but as confident, structurally complete forms. The dominant crystal stands out immediately, commanding attention through its size, flawless termination and eye clean interior. Its transparency allows light to penetrate deeply, creating internal reflections that animate the crystal from within rather than merely across its surface. Surrounding crystals echo this same quality, reinforcing the impression of a coherent and exceptionally high grade crystallisation event. This type of dioptase is no longer formed in modern conditions. Specimens of this calibre originate almost exclusively from historic extractions and old collections, making each surviving example a finite and increasingly scarce witness to Tsumeb’s legendary mineral wealth. Unlike emeralds, which continue to be mined, treated and commercialised at scale, Tsumeb dioptase exists outside industrial repetition. Its value is rooted in geological rarity, locality prestige and natural perfection rather than market familiarity. The matrix, composed primarily of pale calcite with associated quartz, serves as a natural stage rather than a distraction. Its lighter tones amplify the intensity of the green crystals, while its irregular texture provides a geological context that feels authentic and untouched. The contrast between the luminous green dioptase and the subdued matrix enhances the specimen’s three dimensional presence and visual balance. Entirely natural, unpolished and untreated, this specimen stands as a powerful reminder that true rarity in minerals is not defined by gemstone tradition, but by the convergence of colour, crystallisation quality and provenance. This dioptase does not imitate emerald. It surpasses it in mineralogical significance, standing as one of the most iconic copper silicate expressions ever discovered. Specifications: • Weight: 26.88 g • Dimensions: 44 × 38 × 28 mm • Origin: Tsumeb Mine, Namibia • Primary mineral: Dioptase • Associated minerals: Calcite, Quartz • Crystal habit: Well developed prismatic crystals with complete terminations • Colour: Intense emerald green • Colour saturation: Very high and consistent • Transparency: Translucent to transparent • Clarity: Eye clean crystals • Lustre: Vitreous • Matrix: Pale calcite with quartz associations • Condition: Natural, unpolished, untreated Notable Points: • Fully terminated dioptase crystals with exceptional structural definition • Dominant crystal with perfect termination and eye clean interior • Emerald green colour of remarkable saturation and purity • Transparency allowing strong internal light interaction • Classic and highly sought after Tsumeb dioptase habit • Strong three dimensional crystal presence • Excellent contrast between vivid green crystals and pale matrix • Specimen sourced from a historically exhausted world class locality • No treatments, stabilisation or enhancement of any kind • Mineral quality exceeding typical gemstone colour comparisons Collector’s Interest: This specimen is aimed at advanced collectors who understand that Tsumeb dioptase occupies a category of its own. Pieces of this calibre combine gemstone level colour with museum grade crystallisation and one of the most prestigious mineral localities ever documented. As high quality Tsumeb material continues to disappear into long term collections, examples with fully terminated, eye clean crystals and this level of colour intensity have become increasingly difficult to obtain. This is not a decorative mineral, but a reference piece for serious collections. Lapidary Potential: This specimen has no lapidary intention and must remain entirely intact. Any cutting or alteration would permanently destroy the crystallographic integrity and historical value of the piece. Its highest and only expression is as a natural collector specimen, preserved for display, study and high level mineral photography. ——————— Shipping and Handling: All orders are shipped by Portuguese National Post. • Dispatch time: within 1 to 3 business days after payment confirmation to Catawiki • Transit time with CTT service: between 5 to 7 business days within europe and worldwide, depending on destination national post. • A tracking number is always provided Photography and transparency: All photographs are taken under controlled lighting conditions using a macro lens, carefully selected to present each specimen as accurately as possible. No filters, colour enhancement, or artificial saturation are applied. The lighting setup uses a calibrated 5500K light source, replicating neutral daylight to reveal natural tones, surface features, and internal characteristics. Under warmer or weaker indoor lighting, colours may appear slightly different, which is normal. The purpose of this photographic process is documentation and representation, not visual enhancement. Images are intended to reflect the specimen faithfully as it appears under balanced natural light conditions. Identification and ethics: All specimens offered are natural and described to the best of our knowledge, based on direct sourcing, professional experience, and information provided by trusted suppliers working at the origin. Every effort is made to ensure transparency and accuracy regarding identification, locality, and general characteristics, avoiding misleading statements about treatment, provenance, or nature. Customs and import taxes: Any customs duties, import fees, or local taxes applied by the destination country are entirely the responsibility of the winning bidder. These charges are not included in the auction price or shipping cost and are determined by the buyer’s local authorities. Guarantee and resolution: Customer satisfaction is important. In the unlikely event of an issue such as loss, damage, or discrepancy, please contact us promptly through Catawiki’s messaging system. Each case is handled individually and fairly, with appropriate solutions offered when justified. Appreciation and commitment: We sincerely thank you for your trust. Our work focuses on careful selection, accurate representation, and respectful presentation of mineral specimens with character and interest. Each piece is chosen for its individual qualities rather than speculative or financial considerations. We aim to provide a transparent, reliable, and consistent experience for collectors at all levels. With gratitude, GemPulse Minerals