Question

question 2
what is streak in mineralogy?
the color of powder produced when a minerals is scraped on unglazed porcelain
the lines visible within a minerals surface
the way light reflects off a minerals surface
the pattern created when a mineral breaks

Explanation:

In mineralogy, streak is defined as the color of the powder produced when a mineral is scraped on unglazed porcelain. This can be a more reliable diagnostic property than the mineral's surface color as it is less affected by impurities and surface - weathering.

Answer:

The color of powder produced when a minerals is scraped on unglazed porcelain