what material's streak
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. A streak is usually obtained by dragging a sharp edge, grain, or point of a crystal across a streak plate â which is simply an unglazed piece of porcelain tile, such as those used in bathrooms and kitchens.