{"product_id":"vivianite-green","title":"Vivianite green","description":"\u003cp\u003e\u003cstrong\u003eVivianite green\u003c\/strong\u003e is a natural pigment powder made from a greenish variety of vivianite, the hydrated iron phosphate mineral, giving a soft, muted marsh green. Vivianite's color ranges from pale blue to deep indigo and greenish tones, depending on how far its iron has oxidized. It is a rare historic mineral color for oil, egg tempera, watercolor, gouache and acrylic.\u003c\/p\u003e\n\u003ch2\u003eKey facts\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e muted marsh green (olive gray-green)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePigment type:\u003c\/strong\u003e Natural mineral pigment (iron phosphate)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComposition:\u003c\/strong\u003e hydrated iron(II) phosphate, Fe\u003csub\u003e3\u003c\/sub\u003e(PO\u003csub\u003e4\u003c\/sub\u003e)\u003csub\u003e2\u003c\/sub\u003e·8H\u003csub\u003e2\u003c\/sub\u003eO\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 5.5–7.5 on the Blue Wool Scale, depending on humidity and temperature (supplier data)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemical resistance:\u003c\/strong\u003e alkali 3\/5, lime 3\/5, acid 1\/5 (supplier data, 5 = best); dissolves in strong acids; lime darkens it\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSuitable for:\u003c\/strong\u003e oil, acrylic, egg tempera, watercolor, gouache\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot recommended for:\u003c\/strong\u003e fresco and lime plaster (lime darkens it); encaustic and other hot techniques (heat above about 70 °C alters it)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e 25 g jar · 1 kg bag\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eHow to use\u003c\/h2\u003e\n\u003cp\u003eStir the powder into your binder with a palette knife: egg yolk for tempera, gum arabic for watercolor and gouache, acrylic medium, or linseed oil. Vivianite is very soft, so it disperses with little effort and should not be ground hard. Its quiet green is useful for subdued landscape greens and shadows, and in oil it turns somewhat darker. Keep it away from lime, acids and heat above about 70 °C, and store it dry and closed.\u003c\/p\u003e\n\u003ch2\u003eAbout vivianite\u003c\/h2\u003e\n\u003cp\u003eVivianite forms in waterlogged, oxygen-poor places such as peat bogs, clays and bog iron ores, often as soft earthy lumps that change color in air. As blue ochre it has been used since Roman times and appears in medieval wall paintings and polychromy in Germany and England and in Dutch Golden Age paintings, where some of it has turned greenish over time.\u003c\/p\u003e\n\u003ch2\u003eSafety\u003c\/h2\u003e\n\u003cp\u003eHandle 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 this vivianite green rather than blue?\u003c\/h3\u003e\n\u003cp\u003eVivianite's color depends on how far its iron(II) has oxidized: it ranges from pale blue to deep indigo and greenish tones. This natural variety is greenish; chemically it is the same iron phosphate as our Vivianite blue and grey.\u003c\/p\u003e\n\u003ch3\u003eIs it lightfast?\u003c\/h3\u003e\n\u003cp\u003eModerately. Our supplier rates vivianite 5.5–7.5 on the Blue Wool Scale depending on humidity and temperature, so protect finished work from strong sun, damp and heat.\u003c\/p\u003e\n\u003ch3\u003eCan I use it in fresco?\u003c\/h3\u003e\n\u003cp\u003eNo. Contact with lime darkens vivianite, so keep it to oil, tempera, watercolor, gouache and acrylic.\u003c\/p\u003e","brand":"COLIBRI PIGMENTS LLC","offers":[{"title":"25g","offer_id":51694675362039,"sku":null,"price":18.9,"currency_code":"USD","in_stock":true},{"title":"1kg","offer_id":51696541729015,"sku":null,"price":660.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0643\/6696\/9079\/files\/vivianite-green.jpg?v=1793370350","url":"https:\/\/colibripigments.com\/products\/vivianite-green","provider":"Colibri Pigments","version":"1.0","type":"link"}