De-oxidation
Iron bearing minerals which oxidise to red/brown Iron Oxides (rusts).
Red to reddish brown as for most iron oxides.
Gold will be gold inside. Iron may vary some based on oxidation and the impurities mixed in with the metal, but is typically going to be 'rust' brown.
Hematite is a mineral made of iron and oxygen. It can be gray, red, or brown.
Iron precipitate can vary in color depending on the oxidation state of the iron. It can appear as orange, brown, or red in color.
Mars is often depicted as reddish due to iron oxide (rust) on its surface. While there are some areas that may appear brown, overall the dominant color of Mars is red.
Most iron III compounds are yellow except for iron III oxide and iron III hydroxide which is reddish brown
Iron-rich limestone can range in color from rusty red to brown or yellow, depending on the amount of iron present. The iron minerals in the limestone can oxidize and create different hues of color.
Red soil is typically reddish-brown in color due to its high iron oxide content. This iron oxide gives the soil its characteristic reddish hue.
Fe2O3 Hexagonal hardness 5-6 streak red to red/brown.
Pure iron is grey. Iron compounds have different colours, for example iron chloride is yellow, iron(II) hydroxide is green and iron(III) oxide is red-brown.
Iron oxide typically appears as a reddish-brown powder or solid. It can range in color from a bright rusty red to a darker brown, depending on its composition and the presence of impurities. Iron oxide is commonly found in nature as the mineral hematite, which exhibits a metallic luster.