Question

Why can't color alone be used to identify most minerals?

Answer 1

It is common for one mineral to be naturally found in more than one color. Different minerals may also be the same color.

Explanation:

It is common for one mineral to be naturally found in more than one color.

For example, the minerals below are all calcite:

Different minerals often have the same color. For example, if you used color alone to identify the two minerals below, you might conclude this was the same mineral, but the first one is barite and the second is dolomite.

Using color alone to identify a mineral could lead to an inaccurate conclusion. The hardness of the mineral, luster, cleavage, fracture, how it reacts to an acid, and other traits can be used to identify what the mineral is.

To read more about the issue of color and minerals, see this link.