665.5 Mohs = 6.52 HRC
| Mohs | HRC |
|---|---|
| 650.5 Mohs | 6.38 |
| 655.5 Mohs | 6.43 |
| 660.5 Mohs | 6.48 |
| 665.5 | 6.52 |
| 670.5 Mohs | 6.57 |
| 675.5 Mohs | 6.62 |
| 680.5 Mohs | 6.67 |
665.5 Mohs = 6.52 HRC
1 HRC ≈ 10.2 HV · 1 HRB ≈ 1.8 HV · 1 Mohs ≈ 0.1 HV — approximate; real conversions vary by material per ASTM E140