<prompt> Fingqa isihloko: Imidwebo yakhe ingenye yezinto eziyigugu kakhulu emhlabeni - nokho eminingi yayo iyaphela kancane kancane. Manje ososayensi baye bathola ukuthi umsebenzi wobuciko kaVincent Van Gogh uba isisulu sokukhetha komculi imibala ayeyisebenzisa emidwebweni yakhe. Baye bathola ukuthi amaminerali angavamile embala obomvu ogqamile asetshenziswa umdwebi wamaDashi uphenduka abe mhlophe njengoba ehlukana abe amakristalu amhlophe anemifantu. Skrolela phansi ukuze ubone ividiyo. Imibala e-Sunflowers ka-Van Gogh, izinguqulo zayo ezimbili eziboniswe ngenhla embukisweni eNational Gallery, kuyesatshwa ukuthi nayo ishintshile njengoba ama-pigment aphuzi nabomvu eye ahlehla ngokuhamba kwesikhathi. Kuye kwatholakala ukuthi amasampula emidwebo kaVan Gogh aqukethe i-plumbonacrite eyiminerali ene-lead esebenza nge-carbon dioxide esemoyeni. Bathi leli minerali liyisixhumanisi esilahlekile esingase sichaze ukuthi kungani upende obomvu oqoshiwe, owaziwa ngokuthi ubuncane, uba mhlophe. Umthofu obomvu akuwona umbala wokuqala owatholakala emsebenzini kaVan Gogh ongakwazi ukumelana nesikhathi. Muva nje abacwaningi baveze ukuthi umbala obomvu wasolwandle naye ayewusebenzisa ubulokhu unyamalala. Lokhu kwabenza baphetha ngokuthi ama-iris aluhlaza okwesibhakabhaka eField with Irises near Arles, ayidweba ngo-1888, ekuqaleni ayenombala onsomi. Abaphathi beVan Gogh Musuem e-Amsterdam nabo baye bathola ukuthi imibala eseGumbini likaVan Gogh lokulala nayo iyafiphala phakathi nomsebenzi wokuvuselela lo mdwebo. Bathola ukuthi ochungechungeni lwezincwadi eziya kumfowabo nodadewabo, uVan Gogh wachaza ngokuningiliziwe imibala egqamile yegumbi lakhe. Lokhu kwavumela ososayensi ukuba bakhe kabusha indlela lo mdwebo owawuyobe ubukeka ngayo ekuqaleni. Bathola ukuthi phansi okunsundu okukhanyayo kwakufanele kube nombala ocebile onsomi nophesheya kuyilapho izindonga eziluhlaza okwesibhakabhaka ekuqaleni zazinombala osawolintshi obomvu nophephetha. Umsebenzi wangaphambilini kaProfesa Janssens uye wabonisa nokuthi upende ophuzi ogqamile, owaziwa ngokuthi i-chrome yellow, emidwebweni kaVan Gogh nawo uye washintsha umbala. Lapho ithimba lakhe liyifaka ekukhanyeni kwe - ultraviolet, lathola ukuthi i - pigment enombala ophuzi ophuzi ophuzi yayisiba nombala onsundu ngokushokoledi. Ukholelwa ukuthi...  <response>: Kutholakale ukuthi i-red lead pigment esetshenziswe nguVincent van Gogh iyaphela. Ukungcola okuphakathi kopende kungenzeka kwabangela ukusabela kwamakhemikhali elangeni. Ososayensi bathole ukuthi kwakheka amaminerali angavamile anesisekelo somthofu kule upende. Lokhu bese kuvumelana ne - carbon dioxide evela emoyeni ukuze kwakheke amakristalu amhlophe. Baxwayisa ngokuthi imidwebo eminingi yomculi ingase ibe sengozini yalenqubo. Bahlola i-Wheat Stack Under a Cloudy Sky futhi bathola ukuthi yayiphelile. 