Question

Which one of the following sets is not correctly matched?

• A. Cuprite, haematite – oxide ores
• B. Calamine, siderite – carbonate ores
• C. Magnetite, malachite – silicate ores
• D. Sphalerite, fool’s gold – sulphide ores

Hint:

Silicates are compounds containing silicon-oxygen tetrahedra. Magnetite and malachite do not belong to this category.

Answer 1

The Correct Option is C

Step 1: Understanding ore classification.
- Cuprite (Cu$_2$O) and haematite (Fe$_2$O$_3$) are oxides.
- Calamine (ZnCO$_3$) and siderite (FeCO$_3$) are carbonates.
- Magnetite (Fe$_3$O$_4$) is an oxide, not a silicate. Malachite (Cu$_2$(OH)$_2$CO$_3$) is a carbonate.
- Sphalerite (ZnS) and fool’s gold (FeS$_2$) are sulphides.