Corundum vs Diamond

Property Corundum Diamond
화학식 Al2O3 C
결정계 Trigonal Cubic (Isometric)
광물 분류 04 Oxides and Hydroxides 01 Native Elements
모스 경도 9.0 10.0
색상 Red (ruby), blue (sapphire), various colors Colorless, yellow, brown, blue, green, pink
광택 Adamantine Adamantine
조흔색 Colorless None
투명도 Transparent Transparent
벽개 None Perfect octahedral {111}
단구 Conchoidal to uneven Conchoidal

Key Differences

  • Diamond (hardness 10) is harder than corundum (hardness 9) — the hardest natural mineral vs. the second hardest.
  • Diamond is pure carbon; corundum is aluminum oxide (Al2O3).
  • Diamond crystallises in the cubic system; corundum is trigonal.
  • Both are used as abrasives, but diamond abrades corundum, not vice versa.
  • Corundum gem varieties are ruby and sapphire; diamond gems are simply called diamonds.

Related Comparisons

← All Comparisons