**Complimentary Specimens** As a gesture of appreciation only, winning lots with a final hammer price above €50 will include one small additional mineral offered entirely free of charge. —————— Description: As a crystallised fragment lifted from the slopes of Kilimanjaro at dawn, this tanzanite rises with the quiet authority of something only Tanzania can offer to the world. Small in scale yet monumental in expression, it is a crystal that concentrates within just a few millimetres the absolute rarity of a mineral found exclusively within a narrow geological belt of the Merelani Hills. The prismatic habit is exemplary. The faces develop with near architectural geometric precision, forming a harmonious vertical body with an almost quadrangular cross section, culminating in a perfectly preserved natural termination. The edges are sharp, the vertices clean, and the symmetry of the termination reflects stable and uninterrupted crystal growth. Considering the perfect cleavage typical of zoisite, the structural integrity of this specimen is particularly remarkable. The colour is extraordinary. Between deep midnight blue and intense bluish violet, the crystal displays the classic pleochroism of high quality tanzanite. From different angles, the tone subtly shifts between dominant blue and saturated violet nuances, creating a living and dynamic chromatic vibration. This variation is not superficial but structural, resulting from the presence of vanadium within the crystal lattice and from the way light interacts with the orthorhombic system of the mineral. Transparency is high for the size of the crystal, allowing light to enter and reveal internal growth planes and natural inclusions that confirm its geological authenticity. The vitreous lustre is strong, particularly along the edges and termination faces, where reflections become almost electric under direct illumination. Merelani Hills Block D is the global epicentre of tanzanite. Formed approximately 585 million years ago during metamorphic events associated with the Pan African orogeny, this region has produced the most celebrated tanzanites in the world. Block D is historically recognised for crystals displaying superior colour saturation, sharper morphological definition and greater structural stability. The geographical exclusivity of tanzanite, confined to only a few square kilometres in Tanzania, grants each specimen a status of global rarity. This crystal does not impress through size. It impresses through perfection, through definition, through structural purity, and through the intensity of colour concentrated within an almost ideal form. It is a piece that demonstrates how, in mineralogy, excellence does not depend on scale, but on the harmony between form, colour and integrity. Specifications: • Weight: 0.12 g • Weight in carats: 0.60 ct • Dimensions: 7 x 4.5 x 4 mm • Origin: Merelani Hills – Block D, Tanzania • Mineral: Tanzanite • Crystal system: Orthorhombic • Crystal habit: Well defined prismatic single crystal • Termination: Fully terminated natural crystal • Colour: Midnight blue with violet blue pleochroic nuances • Colour origin: Vanadium chromophore within the crystal lattice • Transparency: Transparent to locally translucent • Lustre: Strong vitreous • Condition: Natural, unpolished, untreated NOTABLE POINTS: • Exclusive gemstone variety found only in Tanzania • Sourced from Merelani Hills Block D, the most renowned tanzanite locality • Well defined prismatic habit with near quadrangular cross section • Fully preserved natural termination with sharp edges and clean vertices • Strong pleochroism showing midnight blue and violet blue tonal shifts • Excellent colour saturation for a sub centimetre crystal • High structural integrity despite the perfect cleavage typical of zoisite • Transparent body revealing natural growth planes and inclusions • Intense vitreous lustre enhancing edge reflections • No visible cleavage openings or structural weaknesses • Compact yet visually powerful specimen • Geologically authentic metamorphic formation • Formed approximately 585 million years ago during Pan African orogenic events • Mineralogically significant example of vanadium bearing zoisite • Superior display presence for a crystal under 1 carat COLLECTOR’S INTEREST: Crystals of this calibre, with full natural termination and strong pleocroic expression, are considerably rarer than fragment material destined for faceting. Most tanzanite entering the market is broken or trimmed for gemstone production. Intact, well proportioned crystals from Block D are increasingly scarce. For collectors focused on locality significance, structural integrity and chromatic intensity, this specimen represents a refined and geologically honest acquisition. Its rarity is not only commercial but geological: a gemstone variety restricted to a single small region on Earth. LAPIDARY POTENTIAL: Although the colour and clarity would technically allow selective faceting, any cutting would permanently erase the defining attributes of this crystal: its natural termination, prismatic geometry and structural authenticity. Its highest value lies in preservation. In its untouched state, it embodies both geological rarity and morphological perfection. This is a crystal meant to be admired, not reduced. —————— 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