The mineral that causes yellowing of teeth is ______.

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the mineral that causes yellowing of teeth.

2. **Understand the Context**: Yellowing of teeth can be caused by various factors, including dietary habits, oral hygiene, and certain minerals.

3. **Recall Relevant Information**: One specific mineral that is known to affect the color of teeth is fluorine.

4. **Explain the Role of Fluorine**: Fluorine, when present in excess, can lead to a condition known as dental fluorosis, which causes yellowing or discoloration of the teeth.

5. **Consider Sources of Fluorine**: Fluorine can be found in fluoridated water, certain medications, and can also be ingested through smoking or poor dental hygiene.

6. **Conclude with the Answer**: Therefore, the mineral that causes yellowing of teeth is fluorine.

**Final Answer**: The mineral that causes yellowing of teeth is **fluorine**.

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