$A$ mineral is called an ore if

Which one of the following is not an ore of aluminium?

Match List-$I$ with List-$II$.

List-$I$ (Ores)	List-$II$ (Composition)
$a$. Haematite	$i$. $Fe_{3}O_{4}$
$b$. Magnetite	$ii$. $ZnCO_{3}$
$c$. Calamine	$iii$. $Fe_{2}O_{3}$
$d$. Kaolinite	$iv$. $[Al_{2}(OH)_{4}Si_{2}O_{5}]$

Choose the correct answer from the options given below:

Among the following ores: Bauxite,Siderite,Cuprite,Calamine,Haematite,Kaolinite,Malachite,Magnetite,Sphalerite,Limonite,Cryolite,the number of principal ores of iron is $......$

The ore carnalite is represented by the structure:

Naturally occurring substances from which a metal can be profitably (or economically) extracted are called