A streak plate may be used to identify which mineral property?
A streak plate is used to identify the property known as "streak" in minerals. The streak refers to the color of a mineral when it is powdered or scratched against a porcelain plate or unglazed ceramic tile, which is usually white or light-colored.
To use a streak plate for identification purposes, you can follow these steps:
1. Select a clean streak plate: Streak plates are typically made of unglazed porcelain or ceramic. Ensure that the plate is clean and free from any previous mineral residue.
2. Obtain a mineral sample: Choose a mineral specimen that you want to identify and examine its physical characteristics, such as color, hardness, and luster.
3. Test the streak: Holding the streak plate at a slight angle against a solid surface, rub the mineral against the plate with moderate pressure. This creates a powdered streak on the plate's surface.
4. Observe the color: Examine the color of the streak left by the mineral on the streak plate. It may or may not match the color of the mineral itself. Note that some minerals have a white or colorless streak.
5. Compare the streak color: Compare the color of the streak with the known streak colors of various minerals. You can refer to mineral identification charts or online resources to determine the possible identification of the mineral based on its streak color.
It's important to note that streak color can sometimes be different from the color of the whole mineral, as impurities can affect the coloration. Therefore, the streak test can be a useful additional tool in mineral identification alongside other properties like hardness, cleavage, and specific gravity.