GEOLOGY

Detailed explanation-1: -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-2: -Hardness. The ability to resist being scratched-or hardness-is one of the most useful properties for identifying minerals. Hardness is determined by the ability of one mineral to scratch another. Federick Mohs, a German mineralogist, produced a hardness scale (table 5) using a set of ten standard minerals.

Detailed explanation-3: -Streak is more reliable than color for the identification of minerals. Streak is determined by rubbing some of the mineral against an unglazed ceramic tile called a streak plate.

Detailed explanation-4: -The color of a mineral in powdered form is called the mineral’s streak. To find a mineral’s streak, the mineral is rubbed against a piece of unglazed porcelain called a streak plate. The mark left on the streak plate is the streak.

Detailed explanation-5: -An unglazed piece of porcelain, such as a tile, used to test the characteristic streak of minerals by rubbing the mineral across the tile. Streak plates have a hardness of about 6.5 on the Mohs scale and cannot be used for testing harder minerals.