Question: What compounds also known as ferric oxide is used in ceramic colorants?
Context: Iron(III) oxide or ferric oxide is the inorganic compound with the formula FeO.  It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare, and iron(II,III) oxide (FeO), which also occurs naturally as the mineral magnetite.  As the mineral known as hematite, FeO is the main source of iron for the steel industry.  FeO is ferromagnetic , dark red, and readily attacked by acids.  Iron(III) oxide is often called rust, and to some extent this label is useful, because rust shares several properties and has a similar composition.  To a chemist, rust is considered an ill-defined material, described as "hydrated" ferric oxide. Ferric subsulfate solution is a styptic or hemostatic agent used after superficial skin biopsies.  Ferric subsulfate solution is also known as basic ferric sulfate solution or Monsel's solution.  It has a recognised formula published in United States Pharmacopeia 29. Mars Black is an iron oxide pigment developed in the 20th century.  Also known under the names of black iron oxide, magnetic oxide, Pigment Black 11, and ferrous ferric oxide (FeO), it has no known health hazards and is considered non-toxic, with an ASTM lightfastness rating of I.  It is more opaque and less toxic than other black pigments.  Artists' paint manufacturers have rated it one of the most satisfactory black pigments for acrylic paints with regard to opacity, lightfastness, and permanence.  It takes its name from Mars, the god of war and patron of iron. Fatty alcohol polyglycol ethers with a narrow homolog distribution, which are also known as narrow-range ethoxylates (NRE), are known nonionic surfactants, which are industrially produced, for example, by addition of ethylene oxide onto fatty alcohols in the presence of suitable catalysts (layer compounds which have been calcined or hydrophobized with fatty acids).  This process can also be carried out on a variety of other hydrophobes and using different alkoxylating compounds (e.g., propylene oxide and butylene oxide) by modifying the catalyst properties. Berkelium forms a number of chemical compounds, where it normally exists in an oxidation state of +3 or +4, and behaves similarly to its lanthanide analogue, terbium.  Like all actinides, berkelium easily dissolves in various aqueous inorganic acids, liberating gaseous hydrogen and converting into the trivalent oxidation state.  This trivalent state is the most stable, especially in aqueous solutions, but tetravalent berkelium compounds are also known.  The existence of divalent berkelium salts is uncertain and has only been reported in mixed lanthanum chloride-strontium chloride melts.  Aqueous solutions of Bk ions are green in most acids.  The color of the Bk ions is yellow in hydrochloric acid and orange-yellow in sulfuric acid.  Berkelium does not react rapidly with oxygen at room temperature, possibly due to the formation of a protective oxide surface layer; however, it reacts with molten metals, hydrogen, halogens, chalcogens and pnictogens to form various binary compounds.  Berkelium can also form several organometallic compounds. Ceramic colorants are added to a glaze or a clay to create color.  Carbonates and oxides of certain metals, characterize most colorants including the commonly used cobalt carbonate, cobalt oxide, chrome oxide, red iron oxide, and copper carbonate.  These colorants can create a multitude of colors depending on other materials they interact with and to which temperature and in which atmosphere they are fired. Uranium dioxide or uranium(IV) oxide (U O ), also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite.  It is used in nuclear fuel rods in nuclear reactors.  A mixture of uranium and plutonium dioxides is used as MOX fuel.  Prior to 1960, it was used as yellow and black color in ceramic glazes and glass. Deoxyepinephrine, also known by the common names N-methyldopamine and epinine, is an organic compound and natural product that is structurally related to the important neurotransmitters dopamine and epinephrine.  All three of these compounds also belong to the catecholamine family.  The pharmacology of epinine largely resembles that of its "parent", dopamine.  Epinine has been found in plants, insects and animals.  It is also of significance as the active metabolic breakdown product of the prodrug ibopamine, which has been used to treat congestive heart failure. A ferrite is a type of ceramic compound composed of iron(III) oxide (FeO) combined chemically with one or more additional metallic elements.  They are both electrically nonconductive and ferrimagnetic, meaning they can be magnetized or attracted to a magnet.  Ferrites can be divided into two families based on their magnetic coercivity, their resistance to being demagnetized.  "Hard ferrites" have high coercivity, hence they are difficult to demagnetize.  They are used to make magnets, for devices such as refrigerator magnets, loudspeakers and small electric motors. "Soft ferrites" have low coercivity.  They are used in the electronics industry to make ferrite cores for inductors and transformers, and in various microwave components.  Ferrite compounds have extremely low cost, being made of iron oxide (i.e. rusted iron), and also have excellent corrosion resistance.  They are very stable and difficult to demagnetize, and can be made with both high and low coercive forces.  Yogoro Kato and Takeshi Takei of the Tokyo Institute of Technology synthesized the first ferrite compounds in 1930. Iron(II) oxide or ferrous oxide is the inorganic compound with the formula FeO.  Its mineral form is known as wüstite.  One of several iron oxides, it is a black-colored powder that is sometimes confused with rust, the latter of which consists of hydrated iron(III) oxide (ferric oxide).  Iron(II) oxide also refers to a family of related non-stoichiometric compounds, which are typically iron deficient with compositions ranging from FeO to FeO.
Answer: iron oxide