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.
Filed under: Geology / Earth Science, Minerals & Crystals, Rocks - Igneous, Sedimentary & Metamorphic on September 17th, 2009 | 2 Comments »
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.
Filed under: Geology / Earth Science, Rocks - Igneous, Sedimentary & Metamorphic on June 11th, 2009 | 1 Comment »
A geyser is a hot spring which ejects hot water a vapors through a crack in the rock.
Filed under: Geology / Earth Science, Minerals & Crystals, Rocks - Igneous, Sedimentary & Metamorphic on March 19th, 2009 | 1 Comment »
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).
Filed under: Geology / Earth Science, Minerals & Crystals on March 16th, 2009 | No Comments »
Rivers are natural water bodies which flow toward another water body such as another river, lake or ocean.
Filed under: Geology / Earth Science on March 13th, 2009 | No Comments »
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.” Staurolite forms in metamorphic rocks […]
Filed under: Geology / Earth Science, Minerals & Crystals on June 26th, 2008 | 2 Comments »