{"product_id":"gabbro-rock","title":"Gabbro rock","description":"\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eGabbro is a coarse-grained durable rock with a crystalline structure. It has many aesthetic and practical uses, e.g. for monuments, gravestones, kitchen bench tops and sea defences.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIgneous:\u003c\/strong\u003e Igneous: Formed from molten magma cooling and solidifying while deep underground (therefore a 'plutonic igneous' rock).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSource location:\u003c\/strong\u003e Tasman Bay. Other locations include Northland, Marlborough and Southland.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSizes:\u003c\/strong\u003e Select Shelf, Hand or Small specimen from the drop-down menu.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e Images are examples of specimens only. Sizes and shapes will vary.\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003e\u003cstrong\u003eMore detail\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003ch4\u003eStructure\u003c\/h4\u003e\n\u003cp\u003eIt has a tightly interlocking, crystalline structure and is made up mostly of dark minerals like pyroxene and calcium-rich plagioclase feldspar, with little or no quartz.\u003c\/p\u003e\n\u003ch4\u003eType\u003c\/h4\u003e\n\u003cp\u003ePlutonic (intrusive) igneous rock – the deep-cooled, coarse-grained version of basalt.\u003c\/p\u003e\n\u003ch4\u003ePhysical properties of gabbro\u003c\/h4\u003e\n\u003cdiv\u003e\n\u003cul\u003e\n\u003cli\u003eColour: Usually dark grey to black, sometimes with a greenish tint; can show small lighter flecks from the feldspar, but overall it looks much darker than diorite.\u003c\/li\u003e\n\u003cli\u003eLustre: When polished, gabbro has a shiny, glassy look and is often sold as “black granite”.\u003c\/li\u003e\n\u003cli\u003eHardness: A very hard, tough rock – about 6–7 on the Mohs hardness scale, similar to quartz.\u003c\/li\u003e\n\u003cli\u003eDensity: Quite heavy and dense, typically around 2.8–3.1 g\/cm³, making it heavier than most granites and diorites.\u003c\/li\u003e\n\u003cli\u003eFracture: Breaks with a granular, slightly uneven surface across its interlocking crystals.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003ch4\u003eGeneral properties of gabbro\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eComposition: Mostly dark pyroxene minerals and calcium-rich plagioclase feldspar, with small amounts of olivine or hornblende; it has low silica content, so it’s classed as a mafic (dark, dense) rock.\u003c\/li\u003e\n\u003cli\u003eTexture: Medium to coarse grained – you can usually see the individual crystals with the naked eye because it cooled slowly underground.\u003c\/li\u003e\n\u003cli\u003eDurability: Very strong and hard-wearing; it resists weathering and physical wear, so it lasts well in buildings and roads.\u003c\/li\u003e\n\u003cli\u003eHeat Resistance: Handles heat well and doesn’t deform easily at high temperatures.\u003c\/li\u003e\n\u003cli\u003eLow Porosity: It doesn’t soak up much water, so it’s less prone to damage from freezing and thawing. \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eUses of gabbro in New Zealand and worldwide\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eRoads and Concrete: Most gabbro is crushed and used as aggregate for concrete, road base, asphalt, and railway ballast because it’s strong and long-lasting. \u003c\/li\u003e\n\u003cli\u003eBuilding Stone: Cut into slabs and polished for building facades, floor tiles, wall cladding, steps, curbs, and paving – often marketed as “black granite”. \u003c\/li\u003e\n\u003cli\u003eLandscaping: Used in gardens and public spaces for paths, steps, retaining walls, cobbles, and decorative features where a dark, hard stone is wanted.\u003c\/li\u003e\n\u003cli\u003eMonuments and Headstones: Polished gabbro is popular for cemetery markers, headstones, and memorials because of its dark colour and resistance to weathering. \u003c\/li\u003e\n\u003cli\u003eSculpture and Interiors: Used for sculptures, kitchen benchtops, and interior design pieces, though its hardness makes it harder to carve than softer stones. \u003c\/li\u003e\n\u003cli\u003eIndustrial Uses: Crushed for drainage stone, fill material, and other industrial applications that need a tough, dense rock. \u003c\/li\u003e\n\u003cli\u003eGeological Interest: Studied by geologists to understand how mafic magmas form layered intrusions and oceanic crust.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Science Resource Box","offers":[{"title":"Small specimen","offer_id":51091956269223,"sku":null,"price":4.9,"currency_code":"NZD","in_stock":true},{"title":"Hand specimen","offer_id":51091956301991,"sku":null,"price":7.95,"currency_code":"NZD","in_stock":true},{"title":"Shelf specimen","offer_id":51091956334759,"sku":null,"price":15.95,"currency_code":"NZD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0534\/1193\/8471\/files\/Gabbro.jpg?v=1785817152","url":"https:\/\/scienceresourcebox.co.nz\/products\/gabbro-rock","provider":"Science Resource Box","version":"1.0","type":"link"}