Question

Which one of the following is the finest quality of iron ore?
A. Haematite
B. Limonite
C. Magnetite
D. Siderite

Answer 1

Hint: It is a stone mineral and one of the fundamental iron metals, with the compound equation Fe3O4. It is one of the oxides of iron, and is ferrimagnetic; it is pulled into a magnet and can be charged to turn into a lasting magnet itself.

Complete Answer:
It is the most attractive of the relative multitude of normally happening minerals on Earth. Naturally-polarized bits of magnetite, called lodestone, will pull in little bits of iron, which is the way antiquated people groups originally found the property of attraction. Today it is mined as iron metal. Little grains of magnetite happen in practically all molten and transformative rocks. Magnetite is dark or tannish dark with a flash of metallic brilliance, has a Mohs hardness of 5–6, and leaves a dark streak. The compound IUPAC name is iron (II, III) oxide and the basic substance name is a ferrous-ferric oxide.
Notwithstanding molten rocks, magnetite likewise happens in sedimentary rocks, including joined iron developments, and in the lake and marine residue as both detrital grains and as magneto fossils. Magnetite nanoparticles are likewise thought to shape in soils, where they presumably oxidize quickly to maghemite. The compound synthesis of magnetite is Fe2+Fe23+O42−. The principal subtleties of its structure were set up in 1915. It was one of the primary precious stone structures to be acquired utilizing X-beam diffraction. The structure is opposite spinel, with O2− particles framing a face-focused cubic grid and iron cations involving interstitial locales. A big part of the Fe3+ cations possess tetrahedral locales while the other half, alongside Fe2+ cations, involve octahedral destinations. The unit cell comprises 32 O2− particles and the unit cell length is ${\text{a}} = 0.839$ nm. Magnetite contains both ferrous and ferric iron, requiring conditions containing halfway degrees of oxygen accessibility to shape.

Thus, option (C) is correct.

Note: Magnetite varies from most other iron oxides in that it contains both divalent and trivalent iron. As an individual from the spinel gathering, magnetite can frame strong arrangements with likewise organized minerals, including ulvospinel (Fe2TiO4), hercynite (FeAl2O4), and chromite (FeCr2O4).