Which of the following is correct statement ?

Options

A. Double chain silicates are known as amphiboles.
B. In cyclic silicates two oxygen atoms per tetrahedron are shared.
C. Orthosilicates contain discrete `(SiO_(4))^(4-)` units.
D. All arer correct statements

Explanation

To solve the question "Which of the following is a correct statement?" regarding silicates, we will analyze each statement provided in the question step by step.

### Step 1: Analyze the first statement
**Statement:** Double chain silicates are known as amphiboles.

**Analysis:**
- Double chain silicates consist of two chains of silicate tetrahedra that are linked together.
- The general formula for double chain silicates is \( \text{Si}_4\text{O}_{11}^{6-} \).
- These silicates are indeed classified as amphiboles.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze the second statement
**Statement:** In the cyclic silicates, two oxygen atoms per tetrahedron are shared.

**Analysis:**
- Cyclic silicates are characterized by silicate tetrahedra that are linked in a ring structure.
- In cyclic silicates, each tetrahedron shares two of its oxygen atoms with neighboring tetrahedra.
- The general formula for cyclic silicates can be represented as \( \text{Si}_n\text{O}_{3n} \).

**Conclusion:** This statement is **correct**.

### Step 3: Analyze the third statement
**Statement:** Orthosilicates contain discrete \( \text{SiO}_4^{4-} \) units.

**Analysis:**
- Orthosilicates are silicates where the silicate tetrahedra are not linked to each other.
- The formula for orthosilicates is indeed \( \text{SiO}_4^{4-} \), representing a single tetrahedron.
- Examples of orthosilicates include minerals like zircon (\( \text{ZrSiO}_4 \)).

**Conclusion:** This statement is **correct**.

### Step 4: Analyze the fourth statement
**Statement:** All the above statements are correct.

**Analysis:**
- Since we have established that the first, second, and third statements are all correct, this statement must also be correct.

**Conclusion:** This statement is **correct**.

### Final Answer
All the statements regarding silicates are correct. Therefore, the answer is option number four: **All are correct statements.**

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