How to Perform a Mineral Streak Test

A streak test is one tool that geologists use to determine the identity of a mineral. The “streak” is the color of the mineral in powdered form. Some minerals will have a streak color that is the same as the outer color of the mineral while others will have a streak color that is very different from the outer color.

Arkose – Beautiful Sedimentary Rock

Arkose is a beautiful sedimentary rock that is typically gray, pink or red. This coarse-grained rock forms when igneous rocks break apart and the pieces travel to a river, lake or ocean.


A geyser is a hot spring which ejects hot water a vapors through a crack in the rock.

Amethyst is one of the most popular minerals with children

Amethyst is a common, purple form of the mineral quartz. Fairly hard, amethyst is a 7 on the Mohs hardness scale which has a range from 1 (softest) to 10 (hardest).

Is a River Young or Old? The Answer is in the Curves!

Rivers are natural water bodies which flow toward another water body such as another river, lake or ocean.

Why do sandstone rocks sometimes have holes in them?

Why do sandstone rocks sometimes have holes in them?

Staurolite – Now this is a cool mineral!

Staurolite is a unique mineral which often forms cross-shaped twinned crystals.  While staurolite is generally brown it has a colorless to grey streak and it is about as hard as quartz (7 to 7.5 on Mohs hardness scale).  The name staurolite comes from the Greek word stauros which means “cross.”Â  Staurolite forms in metamorphic rocks […]