刚玉

Traditional form:

剛玉

Pinyin (reading):

gāngyù

Definitions:

• corundum (mineral)

Characters:

• 刚 - hard, strong, tough; just, barely
• 玉 - jade, gem, precious stone

Traditional characters:

• 剛 - hard, strong, tough; just, barely
• 玉 - jade, gem, precious stone