GENERAL GEOLOGY

Detailed explanation-1: -The color of a mineral’s streak is not always the same as the color of the mineral sample, as shown in Figure 4. Unlike the surface of a mineral sample, the streak is not affected by weathering. For this reason, streak is more reliable than color as an indicator of a mineral’s identity.

Detailed explanation-2: -Streak is simply the color of a mineral powder. Many minerals have a different color when powdered than they do in crystal or massive forms. The color may be entirely different, or it may be a different shade. Quite a few minerals give a powder streak that is lighter in color than the whole crystal or massive pieces.

Detailed explanation-3: -Streak: When a mineral is rubbed firmly across an unglazed tile of white porcelain (a streak plate), it leaves a line of powder, called the streak. The color of the streak varies from mineral to mineral. However, different colored samples of the same mineral always leave the same color streak.

Detailed explanation-4: -A mineral’s streak is the color of the powder left behind when the mineral is scraped across a surface. Geologists use a tile of unglazed porcelain, called a streak plate, as a tool to identify minerals by their streaks. Streak is a better clue to a mineral’s identity than surface color is.