EVERYDAY SCIENCE

Detailed explanation-1: -Hematite, which is black in appearance, leaves a red streak which accounts for its name, which comes from the Greek word “haima", meaning “blood.” Galena, which can be similar in appearance to hematite, is easily distinguished by its gray streak.

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: -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.

Detailed explanation-4: -The streak test is done by scraping a specimen of the mineral across a piece of unglazed porcelain known as a “streak plate.” This can produce a small amount of powdered mineral on the surface of the plate. The powder color of that mineral known as its “streak."