Which of the following is a correct statement ?

Options

A. Calamine is the ore of zinc
B. Pyrolusite is the ore of manganese
C. Cassiterite is the ore of tin
D. Calcite is the ore of calcium

Answer

To determine which of the following statements is correct regarding ores and their respective metals, we will analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement:** Keramine is the ore of zinc.
**Chemical Formula:** Zn2OHO2SiO3
**Content:** Approximately 5-15% zinc.
**Conclusion:** This statement is correct.

### Step 2: Analyze the second statement
**Statement:** Pyrolusite is the ore of manganese.
**Chemical Formula:** MnO2
**Content:** Approximately 63.2% manganese.
**Conclusion:** This statement is correct.

### Step 3: Analyze the third statement
**Statement:** Cassidyrite is the ore of tin.
**Chemical Formula:** SnO2
**Content:** Approximately 78.8% tin.
**Conclusion:** This statement is correct.

### Step 4: Analyze the fourth statement
**Statement:** Calcite is the ore of calcium.
**Chemical Formula:** CaCO3
**Content:** Approximately 40% calcium.
**Conclusion:** This statement is correct.

### Final Conclusion
After analyzing all the statements, we find that:
1. Keramine is the ore of zinc (correct).
2. Pyrolusite is the ore of manganese (correct).
3. Cassidyrite is the ore of tin (correct).
4. Calcite is the ore of calcium (correct).

Thus, all the statements provided are correct.

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