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MINERAL MATTERSMINERAL MATTERS
HOW TO IDENTIFY MINERALS

Introduction
Color
Streak
Transparency
Luster
Hardness
Cleavage
Fracture
Specific Gravity
Crystal Form

Mineral Matters
Regional Minerals

Streak

Large geode lined with amethyst crystals. When a mineral is rubbed firmly across an unglazed tile of white porcelain (a streak plate), it leaves a line of powder. This is called the streak. The color of the streak is always the same, whether or not the mineral has impurities. For example, quartz leaves a white streak, whether it's violet (amethyst), pink (rose quartz), or brown (smoky quartz).

The geode pictured here is lined with amethyst crystals.



Mineral Matters | Kids' Habitat

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