{"product_id":"dioptase-tiger-mammoth-st-anthony-mining-district-pinal-county-arizona-usa-copy","title":"Arfvedsonite (Barkevikite Variety)- Near Hernandez, California, USA","description":"\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eArfvedsonite (Barkevikite Variety)\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003e\u003cspan\u003eNear Hernandez, California, USA\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003e\u003cspan\u003eDimensions:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 4.1 × 4.0 × 2.3 cm\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003e\u003cspan\u003eProvenance:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Original vintage collection label, catalog no. 197, included with specimen. The label identifies the mineral as Arfvedsonite, variety Barkevikite.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAn intriguing specimen featuring abundant dark charcoal-gray to black amphibole crystals embedded in a contrasting white to creamy matrix. The elongated, bladed to prismatic crystals display prominent lengthwise striations and a vitreous to slightly silky luster. Intersecting crystal aggregates create a densely textured surface, while the lighter matrix accentuates the individual crystal formations and their varied orientations.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eArfvedsonite is a sodium-rich amphibole mineral commonly associated with alkaline igneous rocks. Barkevikite is a historical varietal name applied to certain dark amphiboles, particularly those occurring in igneous environments. This vintage specimen preserves an older mineralogical designation, offering an interesting example of the evolving classification of amphibole minerals and the geological diversity of California's mineral localities.\u003c\/span\u003e\u003c\/p\u003e","brand":"The Crystalary","offers":[{"title":"Default Title","offer_id":67782190792835,"sku":"barrydwr9-2of2-197","price":30.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0390\/4634\/8931\/files\/IMG_30943.jpg?v=1791933382","url":"https:\/\/www.thecrystalary.com\/products\/dioptase-tiger-mammoth-st-anthony-mining-district-pinal-county-arizona-usa-copy","provider":"The Crystalary","version":"1.0","type":"link"}