Description: This impressive crystal is a truly colossal example of petroleum bearing Herkimer diamond , a biterminated crystal with a commanding presence and a remarkably lively internal world. Weighing almost forty carats, it shows the classic sharply defined faces and bright glassy lustre that make Herkimer so sought after, yet with an extra twist of character given by the golden petroleum inclusions that glow under ultraviolet light. Under normal illumination the stone presents a clear to slightly smoky body with warm internal tones and attractive veils, while under UV it reveals discrete zones of bright fluorescent response, confirming the presence of trapped petroleum droplets deep inside the crystal. The double termination is well developed on both ends, giving the piece a very balanced geometry and a strong three dimensional feel when rotated in the hand. Internal reflections, subtle rainbows and the interplay between clarity and inclusion create a dynamic visual effect that feels almost gem like despite being a natural rough crystal. The size alone would already make this specimen a centrepiece, but the combination of UV reaction, petroleum inclusions and excellent face definition pushes it into a much higher category, comparable with some of the most desirable petroleum Herkimer material coming from the Pakistan region. For collectors, this is the kind of specimen that anchors an entire sub collection of Herkimer diamonds, offering both size and a textbook example of the petroleum phenomenon. For cutters and designers it also represents an unusual opportunity, since the mass and clarity of several zones could allow the creation of smaller faceted stones that still preserve the story of the original crystal, although many will prefer to keep it intact as a display piece. In either case it is a rare and charismatic crystal, very close to the visual impression of a natural diamond yet unmistakeably quartz in its internal landscape. Specifications: • Weight: 7.92 g • Carat weight: 39.60 ct • Dimensions: 26 × 21 × 19 mm • Origin: Balochistan region, Pakistan • Material: Natural Herkimer diamond quartz • Colour: Clear to slightly smoky with warm internal tones • Transparency: Transparent with localised internal inclusions • UV reaction: Distinct fluorescence due to petroleum inclusions under UV light • Termination: Double terminated crystal • Lustre: Bright vitreous surface lustre • Treatment: None, natural specimen Notable Points: • Colossal size for petroleum bearing Herkimer, almost forty carats of mass • Double termination with well defined natural faces and strong geometry • Clear to slightly smoky body with attractive internal reflections and subtle rainbows • Distinct UV reactive zones confirming petroleum inclusions inside the crystal • Excellent display piece quality, stands out immediately in any collection tray • Strong visual resemblance to a rough diamond while retaining the Herkimer character Collector’s Interest: This specimen unites three highly desirable features in the Herkimer world, namely exceptional size, well formed double termination and confirmed petroleum inclusions with UV response. Pieces that combine all three in such a balanced way are far less common on the market, making this crystal an excellent anchor piece for a specialised Herkimer or petroleum quartz collection and a very convincing candidate for inclusion in a higher tier minerals auction. Lapidary Interest: The stone offers interesting lapidary potential thanks to its generous dimensions and areas of clearer material, suitable for cutting a series of smaller bright stones with a distinctive internal character. However, the rarity of such a large and aesthetically strong petroleum bearing Herkimer will likely persuade most lapidaries and collectors to preserve it as a single intact specimen, where its full story and geometry can be appreciated. ————— Photography and transparency: All photos were taken under controlled light conditions, carefully selected to reproduce the most accurate natural colour of each specimen. No filters, colour enhancement, or artificial saturation were applied. The lighting setup uses a calibrated 5500K light source, which replicates neutral daylight and reveals the true tones and clarity of the mineral. Under weaker or more yellow indoor lighting, colours may appear slightly different, which is normal and expected. The purpose of this setup is to present each specimen exactly as it appears in balanced natural daylight, allowing buyers to appreciate its authentic colour and lustre without distortion. Identification and ethics: All specimens offered are guaranteed natural and as described. Their origin and mineral identification are provided with the most accurate and reliable information available. Every effort is made to ensure that each piece is presented with full transparency, avoiding any misleading details regarding its nature, treatment, or provenance. Shipping and handling: Orders are carefully prepared, with each stone individually protected and placed in a secure rigid box to ensure safe delivery. Shipments are made within 1 to 3 business days after payment confirmation, always with a tracking number provided to the buyer. Each order is handled with professional care from selection to dispatch, ensuring a smooth and trustworthy process. 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 a priority. In the event of any issue, such as loss, damage, or discrepancy, please contact us immediately through Catawiki’s messaging system. We will always find a fair and suitable solution, including refund, replacement, or other commercial arrangements whenever justified. Appreciation and commitment: We sincerely thank you for your trust and preference. Our goal is to continuously bring you some of the most beautiful, unique, and exceptional mineral specimens from around the world. Each piece is carefully selected for its quality and character, ensuring that every purchase meets the highest standards. Your satisfaction and confidence are our top priorities, and we will always strive to exceed your expectations with every order. With gratitude, GemPulse Minerals