For the majority of minerals,the streak color obtained when the mineral is scratched against a porcelain plate is ________.
A)only useful if the mineral is softer than porcelain
B)more variable than the color in a hand sample among crystals
C)not useful because the porcelain will often chemically react with the mineral
D)always dark brown or black

Question

Quizplus · Accepted Answer

The streak color obtained when the mineral is scratched against a porcelain plate is mostly useful if the mineral is softer than porcelain. This is because the color left behind is a more reliable indicator of the mineral's true color, independent of any impurities or weathering on its surface.

For the Majority of Minerals,the Streak Color Obtained When the Mineral