Clue: It's around 6 on the Mohs scale

Answer: OPAL

Length: 4

---

Similar Clues:

• Item on the Beaufort Scale (GALE with 4 letters)
• Item in Beaufort's scale (GALE with 4 letters)
• It's 10 on the modified Mohs scale of hardness (GARNET with 6 letters)
• High on the Mohs scale (HARD with 4 letters)
• Somewhat high on the Mohs' scale (HARD with 4 letters)
• Mohs scale adjective (HARD with 4 letters)
• Higher on the Mohs scale (HARDER with 6 letters)
• Stone measuring 5.5 to 6.5 on the Mohs scale (OPAL with 4 letters)
• Mid-Mohs scale mineral (OPAL with 4 letters)
• It's 6.5 on the Mohs scale (OPAL with 4 letters)