Which of the following statements about diamond are correct ?
1.It is used as a gem in jewellery because of its ability to reflect light.
2. It is good conductor of electricity .
3. It is used for cutting glass, marble stones and other hard materials.
4.It is used for drilling of rocks.
Select the correct answer using the codes given below.

Options

A. 1,3 and 4
B. 2,3 and 4
C. 1,2 and 3
D. 2 and 4

Explanation

To determine which statements about diamond are correct, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: "It is used as a gem in jewellery because of its ability to reflect light."**
- This statement is **correct**. Diamonds are highly valued in jewelry due to their brilliance and ability to reflect light, which gives them a sparkling appearance.

2. **Statement 2: "It is a good conductor of electricity."**
- This statement is **incorrect**. Diamonds are non-conductive because they do not have free electrons. They are insulators, which means they do not conduct electricity.

3. **Statement 3: "It is used for cutting glass, marble stones and other hard materials."**
- This statement is **correct**. Diamonds are the hardest known natural material, making them ideal for cutting and grinding other hard substances, including glass and marble.

4. **Statement 4: "It is used for drilling of rocks."**
- This statement is **correct**. Diamonds are often used in drill bits for drilling rocks and other hard materials due to their hardness.

### Conclusion:
Based on the analysis:
- Statements 1, 3, and 4 are correct.
- Statement 2 is incorrect.

Thus, the correct answer is **1, 3, and 4**.

### Final Answer:
**Option: 1, 3, and 4 are correct.**

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