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Red ochre, Fe 2 O 3 ·nH 2 O, takes its reddish colour from the mineral hematite, which is an iron oxide, reddish brown when hydrated. [7] Purple ochre is a rare variant identical to red ochre chemically but of a different hue caused by different light diffraction properties associated with a greater average particle size.
Red ochre takes its reddish colour from the mineral hematite, which is an anhydrous iron oxide, and the main ingredient of rust. It was one of the earliest pigments used by man. Hand prints made by using red ochre have been found in the Pech Merle cave in Southern France. They date to between 16,000 and 25,000 BC.
In 2022 a team of South African and French scientists published a study of otjize's physical properties, concluding that "such a red ochre exhibits an exceptional UV filtration and a significant IR reflectivity substantiating its effectiveness as an effective UV-blocking and solar heat IR reflector in support of the low skin cancer rate within the Namibian Himba community".
Red dye No. 3 has been associated with a slew of potential health conditions. In 1990, the Food and Drug Administration (FDA) banned the use of red dye No. 3 in cosmetics due to studies that ...
The California School Food Safety Act, which is a follow-up to the California Food Safety Act and focuses on foods served in schools, will ban red dye No. 40, yellow dyes Nos. 5 and 6, blue dyes ...
Food plot in Germany. A food plot is a planted area set aside to act as a supplementary food source for wildlife. The term was coined by the U.S. hunting and outdoor industries and food plots are most commonly planted for game species. Food plot crops generally consist of but are not limited to legumes (clovers, alfalfa, beans, etc.), grains ...
This red is a tone of Indian red, made like Indian red with pigment made from iron oxide. The first recorded use of English red as a color name in English was in the 1700s (exact year uncertain). [10] In the Encyclopédie of Denis Diderot in 1765, alternate names for Indian red included "what one also calls, however improperly, English Red." [11]
The U.S. Food and Drug Administration is moving to ban the use of Red No. 3 dye in food products. The agency said Wednesday it is amending its color additive regulations to no longer allow the use ...