GEOLOGY

Detailed explanation-1: -Explanation: Streak is an important diagnostic property of many coloured minerals. Simply defined as the colour of the finely powdered mineral as obtained by scratching or rubbing the mineral over rough unglazed porcelain plate.

Detailed explanation-2: -Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.

Detailed explanation-3: -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-4: -Color is usually the first and most easily observed. For many minerals, color is a reliable diagnostic property used for identification.

Detailed explanation-5: -Streak is a more reliable property than color because streak does not vary. Minerals that are the same color may have a different colored streak. Many minerals, such as the quartz in the Figure above, do not have streak.