There is no granite known as "Thunderball Granite." There are several possible explanations for why you might have heard this term:

1. Misinformation: It's possible that you heard a nickname or a mispronounced name for a specific granite variety.

2. Local Name: The name "Thunderball Granite" might be used locally in a specific region, but not recognized globally.

3. Fictional Name: It could be a name made up for a fictional story or a product.

To get a more accurate answer, I would need more information:

* Where did you hear this term?

* What context was it used in?

* Can you describe the granite's appearance? (color, texture, pattern)

With more details, I can help you identify the specific granite you're looking for.