Name the purest from of carbon.

Explanation

**Step-by-Step Solution:**

1. **Understanding Carbon Allotropes**: Carbon exists in several forms known as allotropes. The most common allotropes include diamond, graphite, and fullerenes (like buckminsterfullerene).

2. **Identifying the Purest Form**: Among these allotropes, we need to determine which one is considered the purest form of carbon. The term "purest" typically refers to a form that has the least amount of impurities and a consistent structure.

3. **Defining Diamond**: Diamond is an allotrope of carbon where each carbon atom is tetrahedrally bonded to four other carbon atoms, resulting in a very strong and rigid three-dimensional structure.

4. **Properties of Diamond**: The structure of diamond is homogeneous, meaning it has a uniform composition throughout. This lack of impurities and consistent structure is what makes diamond the purest form of carbon.

5. **Conclusion**: Based on the above points, we conclude that the purest form of carbon is diamond.

**Final Answer**: The purest form of carbon is diamond.

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