There is a great difference in the way different minerals look. Some minerals sparkle in the light while others are dull and boring!! Some minerals are so hard that they can scratch steel while other minerals are so soft that they feel powdery and can be scratched easily by a fingernail. There are many ways that scientists classify or group minerals, in this lesson we are going to study five properties. A property is a characteristic of a mineral. Properties help scientists to better understand how the mineral was formed and also to help identify a mineral. The five properties that we are going to study are luster, hardness, cleavage and fracture, color and streak, and magnetism.
Luster is a property of a mineral that tells how the mineral reflects light. Luster gives you an indication of how "Shiny" a mineral is. The two main ways that geologists categorize a mineral's luster is Metallic and Non-metallic. The luster of a mineral may differ from sample to sample. Metallic minerals shine like metal, while non-metallic minerals vary greatly in their appearance. There are many different descriptions of non-metallic luster, we are going to discuss four. They are pearly, earthy, vitreous (glassy), and greasy. Pearly luster is iridescent, glows like a pearl.
Greasy luster looks like the mineral is covered with grease, the mineral definitely shines. Minerals with an earthy luster have a dull look with no shine. Minerals with an earthy luster look as though they are covered with dirt or dust. The photos above shows examples of these four lusters. Minerals with a vitreous luster (glassy) look like small pieces of a broken glass bottle
Click on the "Color/Streak" button to study another property!
|
Back
Beginning
Questions
Next
To VolcanoWorld