*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: What could be more compelling than a crystal that reveals not only its form, but the very processes that shaped it? This triangular natural diamond emerges as a refined fragment of its original octahedral structure, where geometry, surface texture and geological history converge into a single, coherent expression. The crystal presents a well defined triangular morphology, formed by a dominant octahedral face that rises with clean angular precision. Its outline is sharp yet subtly irregular, particularly along the upper edge where natural interruption has introduced a slight asymmetry, enhancing the individuality of the piece without compromising its structural clarity. Across this principal face, a field of well developed trigons unfolds with remarkable visibility. These triangular etch structures are not superficial markings, but natural dissolution features formed under high temperature conditions deep within the Earth. Each trigon reflects the internal symmetry of the diamond’s cubic lattice, repeating across the surface in a delicate yet highly ordered pattern. They create a textured landscape, where geometry exists both at the macro and micro scale. In contrast to heavily etched or fully matte examples, this specimen displays a balanced interplay between trigonal relief and smoother crystallographic planes. Certain zones appear more refined and reflective, allowing the adamantine lustre to emerge with greater intensity, while adjacent areas retain a more granular micro texture. This variation enhances the optical complexity and gives the surface a dynamic, almost shifting character under light. The body colour is a subtle grey to near colourless tone, with a cool and restrained appearance. Under direct illumination, the crystal reflects light with crisp, controlled flashes, while backlighting reveals a gentle translucency that accentuates both internal structure and surface etching. The trigons become more pronounced in transmitted light, casting fine internal contrasts that deepen the visual experience. The crystal is relatively thin, forming a natural plate like fragment that allows light to pass through with ease. This contributes significantly to the visibility of its internal and surface features, offering a clarity of observation that is rarely achieved in thicker or more massive specimens. Sourced from the diamond bearing region of Lunda Norte in Angola, this piece is consistent with alluvial material that has retained its original crystallographic identity. Unlike rounded stones shaped by prolonged transport, this specimen preserves the sharp geometry and surface detail of its octahedral origin. This is not a diamond defined by brilliance in the traditional sense. It is defined by structure, by symmetry, and by the quiet precision of natural processes recorded on its surface. Specifications: • Weight: 0.03 g • Weight in carats: 0.15 ct • Dimensions: 5 × 5 × 1 mm • Origin: Lunda Norte, Angola • Gem material: Natural diamond • Crystal system: Cubic • Crystal habit: Octahedral fragment with dominant triangular face • Morphology: Thin triangular plate with natural edge irregularity • Surface structures: Well developed trigons with mixed relief • Colour: Grey to near colourless • Colour distribution: Subtle and uniform • Transparency: Translucent to partially transparent under backlight • Lustre: Adamantine • Surface condition: Natural, unpolished • Alteration: None Notable Points: • Well defined trigonal etch patterns Natural trigons are clearly visible across the main face, forming a structured triangular micro relief aligned with the crystal lattice. • Strong triangular crystallographic expression The dominant octahedral face presents a clean geometric triangle, offering immediate visual clarity of diamond structure. • Balanced surface texture Combination of etched trigonal zones and smoother reflective areas enhances both detail and lustre. • Subtle natural edge irregularity The upper boundary shows slight natural interruption, adding individuality without disrupting overall form. • Adamantine lustre on preserved planes Smooth crystallographic surfaces reflect light sharply despite the absence of polishing. • Enhanced optical behaviour under backlight Transmitted light reveals internal translucency and increases trigon visibility. • Thin plate morphology Reduced thickness allows greater light penetration and clearer observation of surface features. • Distinct from heavily resorbed stones Maintains angular geometry and crystallographic integrity rather than rounded erosion. • Consistent Angolan alluvial characteristics Morphology and preservation align with Lunda Norte origin material. • No artificial intervention No cutting, no polishing, no treatment. Entirely natural. • Micro texture richness Surface offers both visual and tactile complexity at different scales. • Geological process visibility Clear evidence of mantle dissolution recorded in the trigonal structures. • High educational value Excellent reference for crystallography and natural diamond surface features. • Strong display appeal Clean triangular form with detailed surface patterning draws immediate attention. • Rare combination of clarity and structure Simultaneous visibility of geometry and surface processes is uncommon in such specimens. Collector’s Interest: Triangular diamonds with clearly expressed trigons occupy a distinct position within natural diamond collecting. They offer more than aesthetic presence. They provide direct visual access to the processes that shaped them. This specimen stands out through its balance. The trigons are neither too subtle nor overwhelmingly dominant, and the preservation of reflective planes alongside etched areas creates a more nuanced and refined surface. This duality enhances both scientific and visual appeal. For collectors focused on crystallography, mantle processes, or natural diamond morphology, this piece represents a compelling and articulate example. Lapidary Potential: Although the material could theoretically be used for very small faceted stones, any intervention would irreversibly remove the trigons and destroy the crystallographic features that define its value. Its true importance lies in preservation, where the full integrity of its natural formation remains intact and visible. ——————- 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