Biotite Facts
Biotite Facts
|
| Interesting Biotite Facts: |
|---|
| Biotite is a primary mineral found in several crystalline igneous rocks including granite, diorite, gabbro, peridotite, and pegmatite. |
| Biotite will also form under metamorphic conditions to form schist and gneiss when argillaceous rocks are exposed to heat and pressure. |
| Biotite is not very resistant to weathering and will transform into clay minerals, it is still sometimes found in sediments and sandstones. |
| It is a mineral that is easily identified and with a little experience, a person can recognize biotite on sight. |
| It is a black mica with perfect cleavage and a vitreous luster on the cleavage faces. |
| When it is separated into thin sheets of mica, the sheets are flexible but will break upon severe bending. |
| When biotite is held help to the light, the sheets are transparent to translucent with a brown, gray, or greenish color. |
| When a brown color is noticed an experienced observer may recognize phlogopite. |
| The black mica minerals named biotite usually cannot be distinguished from one another without laboratory analysis. |
| There are a small number of commercial uses for biotite. Ground mica may be used as a filler and extender in paints, an additive to drilling muds, and in rubber products as an inert filler and mold-release agent. |
| Biotite can also be used as a non-stick surface coating on asphalt shingles and rolled roofing, as well as in the potassium-argon and argon-argon methods of dating igneous rocks. |
| Biotite is sometimes called the "other fools' gold" because tiny flakes of biotite swishing in a gold pan can produce bright bronze-colored reflections in the pan when struck by sunlight. A pin test can quickly distinguish between biotite, which is soft, and gold which is a hard mineral. |
|
Related Links: Facts Minerals Facts Animals Facts Rhyolite Facts Amphibolite Facts Andesite Facts Hornfels Facts Gneiss Facts Schist Rock Facts |