Step 1: Understanding the ores of iron.
Iron ores include hematite, magnetite, and limonite, which are commonly found in nature. These ores contain iron in various oxidation states.
Step 2: Explanation of the options.
- (1) Cassiterite: This is an ore of tin, not iron.
- (2) Limonite: Limonite is an iron ore and a mixture of iron hydroxides.
- (3) Haematite: Haematite is a major ore of iron and consists mainly of iron oxide.
- (4) Magnetite: Magnetite is also an iron ore and contains iron oxide in the form of \( Fe_3O_4 \).
Step 3: Conclusion.
The correct answer is (1) Cassiterite, which is not an ore of iron.