Here are the corrections based on the provided sentences:

1. Mistake: **built**
Correction: **was built**

2. Mistake: **sand**
Correction: **silica** (or another suitable mineral, but "sand" can also be appropriate depending on context)

3. Mistake: **cut out of**
Correction: **made of**

4. Mistake: **the most**
Correction: **the most beautiful**

5. Mistake: **was knowing**
Correction: **knew**

Here’s the completed table with mistakes and corrections:

| Mistakes | Correction |
|--------------------------|------------------------|
| built | was built |
| sand | silica (or correct term) |
| cut out of | made of |
| the most | the most beautiful |
| was knowing | knew |