By Craig Coe
| Factor | What to Check | Why It Matters |
| Diamond quality | 4Cs and overall condition | Establishes the stone’s characteristics |
| Certification | Grading report and issuing laboratory | Supports the diamond’s stated specifications |
| Market conditions | Current demand and pricing | Influences resale potential |
| Buyer expertise | Experience with diamond purchases | Can affect the accuracy of the assessment |
| Final offer | Amount offered and payment terms | Determines your actual return |