การดู
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Mineral identification using Luster, Color, Streak, Hardness and Breakage
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Mineral Identification...Cleavage vs. Fracture
19:17
Rock and Mineral Identification
8:27
Quick Mineral Identification
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MINERALS for Kids - Classification and Uses - Science
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Identifying rocks & minerals using the Mohs hardness test
4:56
Mineral Identification: Hardness
2:28
What minerals show fluorescence under UV light？
