Streak color is the color of the finely-pulverized mineral. Streak plates are
snow-white, unglazed ceramic tiles. You can use the back of a white, glazed tile
from the hardware store to rub the mineral sample to produce a streak.
This only works for minerals which are softer than a ceramic tile (hardness ~
7).
Other References to Mineral Streak
Search the Mineralogy Database
Example Subject Searches
Example:"streak-red*" finds all minerals with a red or reddish
sreak. Example:"streak-reddish-brown" finds all minerals with a
reddish brown streak.