GENERAL GEOLOGY

Detailed explanation-1: -Streak. Streak is the color of the mineral in powdered form. Streak shows the true color of the mineral. In large solid form, trace minerals can change the color appearance of a mineral by reflecting the light in a certain way.

Detailed explanation-2: -The most common physical properties are crystal form, color, hardness, cleavage, and specific gravity. One of the best ways to identify a mineral is by examining its crystal form (external shape).

Detailed explanation-3: -Minerals are colored because certain wavelengths of incident light are absorbed, and the color we perceive is produced by the remaining wavelengths that were not absorbed. Some minerals are colorless. This means that none of the incident light has been absorbed.

Detailed explanation-4: -Context: The streak test is done by scraping an edge 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 color of the streak can help to identify the unknown mineral.

Detailed explanation-5: -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.