688.5 Mohs = 6.75 HRC
| Mohs | HRC |
|---|---|
| 673.5 Mohs | 6.6 |
| 678.5 Mohs | 6.65 |
| 683.5 Mohs | 6.7 |
| 688.5 | 6.75 |
| 693.5 Mohs | 6.8 |
| 698.5 Mohs | 6.85 |
| 703.5 Mohs | 6.9 |
688.5 Mohs = 6.75 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