{"product_id":"gabbro","title":"Gabbro","description":"\u003cp\u003e\u003cstrong\u003eGabbro\u003c\/strong\u003e is a natural gray stone pigment powder ground from gabbro, a dark, coarse-grained igneous rock made mainly of calcium-rich plagioclase feldspar and pyroxene. It gives quiet mineral grays with a slight brownish cast for oil, egg tempera, watercolor, gouache and acrylic and, being lime-fast, it also suits fresco and lime plaster.\u003c\/p\u003e\n\u003ch2\u003eKey facts\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e gray to brownish gray\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePigment type:\u003c\/strong\u003e Natural mineral pigment (ground rock)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComposition:\u003c\/strong\u003e gabbro, an igneous rock of calcium-rich plagioclase feldspar and pyroxene with minor hornblende and olivine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlso known as:\u003c\/strong\u003e black granite (trade name of the building stone)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOpacity:\u003c\/strong\u003e semi-transparent\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightfastness:\u003c\/strong\u003e 8 of 8 on the Blue Wool Scale (supplier data)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemical resistance:\u003c\/strong\u003e alkali 5\/5, lime 5\/5, acid 5\/5 (supplier data, 5 = best)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSuitable for:\u003c\/strong\u003e oil, acrylic, egg tempera, watercolor, gouache, fresco (lime), lime and cement plaster, ceramics\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e 50 g jar · 1 kg bag\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eHow to use\u003c\/h2\u003e\n\u003cp\u003eMix the powder into the binder with a palette knife or muller: linseed oil, egg yolk for tempera, gum arabic for watercolor and gouache, or acrylic medium. For fresco, make a paste with water and paint onto fresh lime plaster; the powder can also tint lime and cement plaster and, according to the supplier, silicate binders. Because it is semi-transparent, gabbro works well in glazes and thin layers: use it for stone and shadow tones, to make neutral grays with white, or to soften bright colors.\u003c\/p\u003e\n\u003ch2\u003eAbout gabbro\u003c\/h2\u003e\n\u003cp\u003eThe name comes from Gabbro, a hamlet near Rosignano Marittimo in Tuscany: in the 1760s it was used for rocks of the Apennine ophiolites, and in 1809 the German geologist Christian Leopold von Buch gave it a narrower meaning. Gabbro has the same chemical composition as basalt but cooled slowly deep underground, so its crystals are coarse. Much of the Earth's oceanic crust is made of gabbro.\u003c\/p\u003e\n\u003ch2\u003eSafety\u003c\/h2\u003e\n\u003cp\u003eGround rock can contain crystalline silica: avoid breathing the dust. Handle dry pigment with care: avoid breathing the dust and contact with eyes. Wear a dust mask (FFP2\/N95) and gloves when working with the powder, work in a well-ventilated area and wipe up spills with a damp cloth. Do not eat, drink or smoke while working; wash your hands afterwards. Keep away from children and pets. For artistic and technical use only — not for cosmetics, food or tattoos.\u003c\/p\u003e\n\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003ch3\u003eIs gabbro the same as basalt?\u003c\/h3\u003e\n\u003cp\u003eChemically, yes: gabbro has the composition of basalt but formed by slow cooling deep underground, so it is coarse-grained, while basalt cooled quickly at the surface.\u003c\/p\u003e\n\u003ch3\u003eCan gabbro be used in fresco?\u003c\/h3\u003e\n\u003cp\u003eYes. The supplier rates it 5 of 5 for lime and alkali resistance and lists it for fresco, lime and cement plaster and silicate binders.\u003c\/p\u003e\n\u003ch3\u003eIs Gabbro a black pigment?\u003c\/h3\u003e\n\u003cp\u003eNo. Although the stone looks dark and is sold as black granite, the ground powder gives grays with a brownish tint rather than a deep black.\u003c\/p\u003e","brand":"COLIBRI PIGMENTS LLC","offers":[{"title":"50g","offer_id":49301792325879,"sku":null,"price":5.9,"currency_code":"USD","in_stock":true},{"title":"1kg","offer_id":49301792358647,"sku":null,"price":105.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0643\/6696\/9079\/files\/gabbro_946faae1-36e5-44eb-87d9-5cde7a579e22.jpg?v=1793366809","url":"https:\/\/colibripigments.com\/products\/gabbro","provider":"Colibri Pigments","version":"1.0","type":"link"}