1. | Can be scratched easily with a fingernail | Sulphur: 1–1-1/2 |
2. | Can be scratched with a fingernail | Amber: 2–3 Ivory: 2–4 |
3. | Can be scratched with a coin | Pearl: 3–4 Coral: 3–4 Malachite: 3-1/2 –4 |
4. | Can be scratched easily with a knife; cannot scratch glass |
Rhodochrosite: 4 |
5. | Can be scratched with a knife; can just scratch glass |
Lapis lazuli: 5–6 Turquoise: 5–6 Opal: 5-1/2 –6-1/2 |
6. | Can be scratched with a steel file; easily scratches window/bottle glass |
Moonstone: 6–6-1/2 Tanzanite: 6-1/2 –7 Peridot: 6-1/2 –7 Zircon: 6-1/2 –7-1/2 |
7. | Easily scratches metal, glass and softer stones |
Citrine: 7 Amethyst: 7 Tourmaline: 7–7-1/2 Garnet: 7–7-1/2 Emerald: 7-1/2 –8 |
8. | Scratches quartz and softer stones | Topaz: 8 Alexandrite: 8-1/2 |
9. | Scratches topaz and softer stones | Ruby: 9 Sapphire: 9 |
10. | Scratches ruby | Diamond: 10 |