"Keiselgurh" is :-

Options

A. Silicified deposits of Diatoms
B. Calcified deposits of Diatoms
C. Pigments of Diatoms
D. Deposits of calcium oxalate in Euglenoids

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Keiselgurh":**
- The term "Keiselgurh" refers to a specific type of earth that is primarily composed of the remains of diatoms, which are a type of algae with silica-based cell walls.

2. **Identifying the Correct Definition:**
- The first option states that Keiselgurh is a "Silicified deposit of diatoms." This is accurate because Keiselgurh is indeed formed from the accumulation of diatomaceous material, which is rich in silica.

3. **Evaluating Other Options:**
- The second option claims it is a "Calcified deposit of diatoms." This is incorrect because Keiselgurh is silicified, not calcified.
- The third option suggests it is "pigments of diatoms." This is also incorrect, as Keiselgurh does not refer to pigments but to the silica deposits.
- The fourth option states it is a "deposit of calcium oxalate in euclinoids." This is incorrect as well, as it does not pertain to Keiselgurh.

4. **Conclusion:**
- After evaluating all the options, the correct answer is that Keiselgurh is a "Silicified deposit of diatoms."

**Final Answer:**
Keiselgurh is a silicified deposit of diatoms.

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