In any mineral, its streak refers to the color of its powder.
Many minerals may vary in colour, for example, quartz, but their streak normally remains the same color. For quartz, this would be white. Likewise, minerals that look alike, like chromite and magnetite which are both greyish black, can be told apart by their streak. Chromite has a brown streak while magnetite has a black streak.
The Streak is also a moth of the family Geometridae.