A blue colored mineral 'lapis lazuli' which is used as a
semi-precious stone is a mineral of the following class :

Options

A. Sodium aluminiosilicate
B. Zinc cobaltate
C. Basic copper
D. Prussian blue

Answer

To determine the class of the mineral 'lapis lazuli', we can follow these steps:

### Step 1: Identify the Composition
Lapis lazuli is primarily composed of lazurite, which has a specific chemical formula. The formula for lazurite is NaCa8Al6SiO24S2. This indicates that it contains sodium (Na), calcium (Ca), aluminum (Al), silicon (Si), and sulfur (S).

**Hint:** Look for key elements in the mineral's formula to help classify it.

### Step 2: Analyze the Components
From the formula, we can see that sodium, aluminum, and silica (SiO2) are significant components. The presence of these elements suggests that lapis lazuli can be categorized based on its chemical composition.

**Hint:** Focus on the main elements present in the mineral to understand its classification.

### Step 3: Classify the Mineral
Given that lapis lazuli contains sodium, aluminum, and silica, it can be classified as a sodium aluminosilicate. This classification is based on the presence of sodium (Na), aluminum (Al), and silicon (Si) in its structure.

**Hint:** Use the names of the elements to form the classification name.

### Step 4: Evaluate Other Options
When considering other potential classifications:
- Zinc Cobaltate does not match because it lacks sodium and aluminum.
- Basic Copper is also incorrect as it does not contain the necessary elements.
- Prussian Blue is a different compound and does not represent the composition of lapis lazuli.

**Hint:** Compare the mineral's composition with the options provided to eliminate incorrect choices.

### Conclusion
Based on the analysis, lapis lazuli is classified as a sodium aluminosilicate due to its significant content of sodium, aluminum, and silica.

**Final Answer:** Lapis lazuli is a mineral of the class Sodium Aluminosilicate.

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