H Harikesh 🎓 Tutor III ⭐ 8.04K Points 📊 Science Q. The hardest substance available on earth is (A) Gold (B) Iron (C) Diamond (D) Platinum 👁️ Show Answer 🔗 Share ⚡Menu ✅ Correct Answer: (C) Diamond You must be Logged in to update hint/solution 💬 Discussion 💬 Comment