The fool's gold is

Options

A. CuS
B. `FeS_(2)`
C. `K_(2)Cr_(2)O_(7)`
D. `HgI_(2)`

Explanation

**Step-by-Step Solution:**

1. **Understanding the Term "Fool's Gold":**
- Fool's gold is a term used to describe a mineral that resembles gold but is not actually gold. It is often mistaken for gold due to its appearance.

2. **Identifying the Chemical Composition:**
- The most common mineral referred to as fool's gold is Pyrite, which has the chemical formula FeS2 (Iron Disulfide).

3. **Characteristics of Fool's Gold:**
- Pyrite has a metallic luster and a pale brass-yellow color, which contributes to its resemblance to gold.
- The luster and color are key features that lead to its misidentification as gold.

4. **Conclusion:**
- Therefore, the correct answer to the question "The fool's gold is" is FeS2.

**Final Answer:**
- The fool's gold is FeS2 (Iron Disulfide).

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