{"product_id":"glauconite-burnt","title":"Glauconite burnt","description":"\u003cp\u003e\u003cstrong\u003eGlauconite burnt\u003c\/strong\u003e is heat-treated natural glauconite: green earth (terre verte, PG23) heated until it turns a light yellowish brown with a greenish tint. It is a soft, semi-transparent khaki earth for glazes, toned grounds and muted warm mixtures in egg tempera, watercolor, oil and fresco.\u003c\/p\u003e\n\u003ch2\u003eKey facts\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e light yellowish brown with a greenish tint (khaki)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePigment type:\u003c\/strong\u003e Natural earth pigment (heat-treated green earth)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColour Index:\u003c\/strong\u003e PG23 (C.I. 77009)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComposition:\u003c\/strong\u003e glauconite, (K,Na)(Fe\u003csup\u003e3+\u003c\/sup\u003e,Al,Mg)\u003csub\u003e2\u003c\/sub\u003e(Si,Al)\u003csub\u003e4\u003c\/sub\u003eO\u003csub\u003e10\u003c\/sub\u003e(OH)\u003csub\u003e2\u003c\/sub\u003e, altered by heat treatment\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlso known as:\u003c\/strong\u003e burnt green earth, burnt terre verte\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOpacity:\u003c\/strong\u003e semi-transparent (glazing)\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 lime 5\/5 (supplier data, 5 = best); strong acids partly dissolve green earth\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\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\u003eMull it with egg yolk, gum arabic, acrylic medium or linseed oil using a palette knife or muller. Applied thinly it is transparent, so it suits glazes, toned grounds and soft warm shadows; build several layers for more coverage. It is lime-proof and can be used in fresco and to tint lime or cement plaster. Mix it with unburnt glauconite for olive half-tones, or with white for warm grays.\u003c\/p\u003e\n\u003ch2\u003eAbout burnt glauconite\u003c\/h2\u003e\n\u003cp\u003eGreen earth turns brown when heated: at around 500 °C it becomes the warm, dark brown known as burnt green earth. This grade is a lighter khaki brown that still keeps a greenish cast. Glauconite itself is an iron-potassium mica that forms in marine sediments; its name comes from the Greek glaukos, \"bluish green\", and green earth has been a painters' pigment since antiquity.\u003c\/p\u003e\n\u003ch2\u003eSafety\u003c\/h2\u003e\n\u003cp\u003eGreen earth is considered non-toxic, but natural glauconite usually contains some quartz (crystalline silica): do not inhale 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\u003eWhy is burnt glauconite brown rather than green?\u003c\/h3\u003e\n\u003cp\u003eHeating turns green earth brown. This heat-treated grade is a light yellowish brown that keeps a greenish tint.\u003c\/p\u003e\n\u003ch3\u003eIs it lightfast and suitable for fresco?\u003c\/h3\u003e\n\u003cp\u003eYes. The supplier rates it 8 of 8 for lightfastness and 5 of 5 for lime resistance, and lists it for fresco and for lime and cement plaster.\u003c\/p\u003e","brand":"COLIBRI PIGMENTS LLC","offers":[{"title":"50g","offer_id":43248847388919,"sku":"","price":5.9,"currency_code":"USD","in_stock":true},{"title":"1kg","offer_id":43248847421687,"sku":"","price":105.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0643\/6696\/9079\/files\/glauconite-burnt_3807edab-a14f-488c-93b0-d5b86aa47354.jpg?v=1793367182","url":"https:\/\/colibripigments.com\/products\/glauconite-burnt","provider":"Colibri Pigments","version":"1.0","type":"link"}