{"product_id":"pyrite-cluster-with-uv-reactive-sphalerite-peru","title":"Pyrite Cluster with UV Reactive Sphalerite – Peru","description":"\u003cp data-start=\"159\" data-end=\"254\"\u003eWeight: 139 g\u003cbr data-start=\"172\" data-end=\"175\"\u003eSize: approx. 6 cm × 5.5 cm × 4 cm\u003cbr data-start=\"209\" data-end=\"212\"\u003eOrigin: Peru\u003cbr data-start=\"224\" data-end=\"227\"\u003eDisplay stand: not included\u003c\/p\u003e\n\u003chr data-start=\"256\" data-end=\"261\"\u003e\n\u003ch2 data-start=\"263\" data-end=\"285\"\u003eAbout This Specimen\u003c\/h2\u003e\n\u003cp data-start=\"287\" data-end=\"610\"\u003eThis is a sculptural multi-generation pyrite crystal cluster displaying sharp metallic cubic faces partially coated in a fine granular sulfide layer. Under UV light the specimen produces vivid orange-red fluorescence across the darker matrix areas, creating a dramatic contrast against the reflective gold crystal surfaces.\u003c\/p\u003e\n\u003cp data-start=\"612\" data-end=\"1007\"\u003eThe piece formed in at least two distinct mineralisation stages. First, well-defined pyrite crystals grew freely within an open hydrothermal cavity, producing the geometric cubic habit typical of slow, stable growth conditions. Later, a second phase deposited micro-crystalline sulfides over parts of the earlier crystal faces, leaving sections exposed while others became textured and darkened.\u003c\/p\u003e\n\u003cp data-start=\"1009\" data-end=\"1214\"\u003eBecause of this, the specimen shows both reflective mirror-like faces and granular mineral growth in a single piece — effectively recording different chemical environments within the same cavity over time.\u003c\/p\u003e\n\u003cp data-start=\"1216\" data-end=\"1309\"\u003eIn daylight it appears architectural and metallic.\u003cbr data-start=\"1266\" data-end=\"1269\"\u003eUnder UV it becomes active and luminous.\u003c\/p\u003e\n\u003chr data-start=\"1311\" data-end=\"1316\"\u003e\n\u003ch2 data-start=\"1318\" data-end=\"1341\"\u003eGeological Formation\u003c\/h2\u003e\n\u003cp data-start=\"1343\" data-end=\"1494\"\u003ePyrite forms in hydrothermal veins when iron-rich fluids circulate through fractures in host rock and crystallise as temperatures and pressures change.\u003c\/p\u003e\n\u003cp data-start=\"1496\" data-end=\"1528\"\u003eFormation sequence visible here:\u003c\/p\u003e\n\u003col data-start=\"1530\" data-end=\"1808\"\u003e\n\u003cli data-start=\"1530\" data-end=\"1589\"\u003e\n\u003cp data-start=\"1533\" data-end=\"1589\"\u003eOpen cavity allowed free-growing cubic pyrite crystals\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1590\" data-end=\"1639\"\u003e\n\u003cp data-start=\"1593\" data-end=\"1639\"\u003eChemical conditions shifted within the fluid\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1640\" data-end=\"1738\"\u003e\n\u003cp data-start=\"1643\" data-end=\"1738\"\u003eSecondary sulfide minerals (including sphalerite-type coatings) deposited over earlier growth\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1739\" data-end=\"1808\"\u003e\n\u003cp data-start=\"1742\" data-end=\"1808\"\u003eHydrocarbon residues became trapped within the later mineral layer\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp data-start=\"1810\" data-end=\"1960\"\u003eThese trapped organic compounds are responsible for the UV fluorescence — not the pyrite itself, but materials introduced during later mineralisation.\u003c\/p\u003e\n\u003cp data-start=\"1962\" data-end=\"2054\"\u003eThis makes the specimen a record of changing geochemistry rather than a single growth event.\u003c\/p\u003e\n\u003chr data-start=\"2056\" data-end=\"2061\"\u003e\n\u003ch2 data-start=\"2063\" data-end=\"2092\"\u003eApproximate Geological Age\u003c\/h2\u003e\n\u003cp data-start=\"2094\" data-end=\"2190\"\u003eThese hydrothermal sulfide deposits formed during Andean mountain building in the Miocene epoch.\u003c\/p\u003e\n\u003cp data-start=\"2192\" data-end=\"2248\"\u003eEstimated age: \u003cstrong data-start=\"2207\" data-end=\"2248\"\u003eapproximately 10–20 million years old\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2250\" data-end=\"2387\"\u003eThis is significantly younger than many quartz geode systems, forming during active tectonic uplift rather than ancient volcanic cooling.\u003c\/p\u003e\n\u003chr data-start=\"2389\" data-end=\"2394\"\u003e\n\u003ch2 data-start=\"2396\" data-end=\"2416\"\u003eUV \u0026amp; Visual Notes\u003c\/h2\u003e\n\u003cp data-start=\"2418\" data-end=\"2676\"\u003e• Bright orange-red fluorescence under longwave UV\u003cbr data-start=\"2468\" data-end=\"2471\"\u003e• Metallic reflective pyrite faces remain non-fluorescent\u003cbr data-start=\"2528\" data-end=\"2531\"\u003e• Strong contrast between crystal faces and matrix\u003cbr data-start=\"2581\" data-end=\"2584\"\u003e• Visible multi-stage mineral growth\u003cbr data-start=\"2620\" data-end=\"2623\"\u003e• Different appearance in daylight vs UV environments\u003c\/p\u003e\n\u003chr data-start=\"2678\" data-end=\"2683\"\u003e\n\u003ch2 data-start=\"2685\" data-end=\"2711\"\u003eRarity \u0026amp; Collectability\u003c\/h2\u003e\n\u003cp data-start=\"2713\" data-end=\"2788\"\u003ePyrite itself is common — sculptural hydrothermal growth sequences are not.\u003c\/p\u003e\n\u003cp data-start=\"2790\" data-end=\"2818\"\u003eWhat elevates this specimen:\u003c\/p\u003e\n\u003cp data-start=\"2820\" data-end=\"3016\"\u003e• Multi-generation crystal formation\u003cbr data-start=\"2856\" data-end=\"2859\"\u003e• Secondary mineral overgrowth preserved\u003cbr data-start=\"2899\" data-end=\"2902\"\u003e• UV reactive hydrocarbon inclusions\u003cbr data-start=\"2938\" data-end=\"2941\"\u003e• Balanced cabinet display form\u003cbr data-start=\"2972\" data-end=\"2975\"\u003e• Peruvian hydrothermal locality material\u003c\/p\u003e\n\u003cp data-start=\"3018\" data-end=\"3131\"\u003eCollector category: Cabinet mineral specimen\u003cbr data-start=\"3062\" data-end=\"3065\"\u003eRarity rating: ★★★☆☆ (Formation interest rather than rare species)\u003c\/p\u003e\n\u003cp data-start=\"3133\" data-end=\"3247\"\u003eThis type of piece appeals to collectors who value formation history and optical behaviour rather than size alone.\u003c\/p\u003e\n\u003chr data-start=\"3249\" data-end=\"3254\"\u003e\n\u003ch2 data-start=\"3256\" data-end=\"3268\"\u003eCondition\u003c\/h2\u003e\n\u003cp data-start=\"3270\" data-end=\"3400\"\u003e• Natural unpolished specimen\u003cbr data-start=\"3299\" data-end=\"3302\"\u003e• Minor contacts typical of extraction\u003cbr data-start=\"3340\" data-end=\"3343\"\u003e• No repairs or enhancements\u003cbr data-start=\"3371\" data-end=\"3374\"\u003e• Stable and display ready\u003c\/p\u003e\n\u003cp data-start=\"3402\" data-end=\"3475\"\u003ePlease review photographs carefully as they form part of the description.\u003c\/p\u003e\n\u003chr data-start=\"3477\" data-end=\"3482\"\u003e\n\u003ch2 data-start=\"3484\" data-end=\"3512\"\u003eWhy This Piece Is Special\u003c\/h2\u003e\n\u003cp data-start=\"3514\" data-end=\"3558\"\u003eMany pyrite specimens are purely reflective.\u003c\/p\u003e\n\u003cp data-start=\"3560\" data-end=\"3584\"\u003eThis one is interactive.\u003c\/p\u003e\n\u003cp data-start=\"3586\" data-end=\"3875\"\u003eIt preserves a chemical transition inside a mineral vein — from clean metallic crystal growth to later mineral coating — and UV light reveals the final stage of that process. The specimen changes character depending on how it is viewed, making it both geological record and visual display.\u003c\/p\u003e\n\u003cp data-start=\"3877\" data-end=\"3919\"\u003eYou will receive the exact specimen shown.\u003c\/p\u003e","brand":"Starshine Minerals","offers":[{"title":"Default Title","offer_id":56705596391768,"sku":null,"price":86.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0969\/4304\/7000\/files\/IMG_7353.jpg?v=1770896614","url":"https:\/\/starshineminerals.co.uk\/products\/pyrite-cluster-with-uv-reactive-sphalerite-peru","provider":"Starshine Minerals","version":"1.0","type":"link"}