Question

Which of the following is not an ore of iron?
A. Haematite
B. Limonite
C. Cassiterite
D. Magnetite

Answer 1

Hint: Iron ores occur in igneous, metamorphic (transformed), or sedimentary rocks in an exceedingly kind of geologic environment. Most are sedimentary, but many are changed by weathering, so their precise origin is difficult to see. Most iron ores are extracted by surface mining.

Complete step by step answer:
A) Haematite: Hematite, also spelt as haematite, it is a common iron oxide with a formula of $F{e_2}{O_3}$ and is easily found in rocks and soils. Hematite is found in black to steel or silver-grey, brown to reddish-brown, or red. It's mined because of the main ore of iron.
B) Limonite: Limonite is an ore consisting of a mix of hydrated iron ($III$ ) oxide-hydroxides in varying composition. The generic formula is often written as $FeO(OH).n{H_2}O$, although this is often not entirely accurate because the ratio of oxide to hydroxide can vary quite widely. Limonite is one of the three principal iron ores, the others being hematite and magnetite, and has been mined for the assembly of iron since a long time.
C) Cassiterite: Cassiterite a tin oxide mineral, $Sn{O_2}$. It's generally opaque, but it's translucent in the crystals. It’s lustre and multiple crystal faces produce a desirable gem. Cassiterite was the main tin ore throughout ancient history and remains the most important source of tin today. Thus we can say that cassiterite isn't an ore of iron.
D) Magnetite: Magnetite could be a rock mineral and one amongst the most iron ores, with the statement $F{e_3}{O_4}$. It's one in each of the oxides of iron, and is ferrimagnetic; it's drawn to a magnet and might be magnetized to become a magnet itself; it's the foremost magnetic of all the naturally-occurring minerals on Earth.

So, the correct answer is Option C.

Note: Iron formation consists of ore like siderite, magnetite, and hematite, with silica within the variety of chert, jasper, etc., generally in bands, but sometimes not distinctly so. The bands of ore are sometimes high-grade but are often mixed with an honest deal of silica, the full making an ore too lean to be used without concentration. The iron formation is known to be of sedimentary origin.