200 likes | 421 Views
Properties Used To identify minerals. Remember ! Rarely is a mineral identified by a single property . Physical Properties Color Streak Luster Hardness. color. Color is the most easily observed mineral property and the least useful! .
E N D
Properties Used To identify minerals
Remember! Rarely is a mineral identified by a single property.
Physical Properties • Color • Streak • Luster • Hardness
color Color is the most easily observed mineral property and the least useful!
Color is not a good property to use to identify a mineral? limestone slate Many minerals have the same color.
color Some exceptions to the color rule would be cinnabar, which is always red, and malachite, which is green.
color Many minerals have a similar color.
color Pure quartz is colorless or white, impurities can make the mineral rose, purple or pink!
streak Streak of a mineral is the color of its powder when rubbed on an unglazed white tile.
streak The streak is often not the same color as the mineral. A minerals color may vary, but the streak rarely will!
The property that means the way the light bounces off the mineral? luster
luster Luster refers to the way a mineral shines in reflected light. Notice the difference between these two minerals?
Metallic Non-metallic Luster How minerals reflect light
luster The mineral on the left has a metallic luster, the one on the right, a nonmetallic luster.
luster There are several terms used to describe nonmetallic luster. Examples could be vitreous, like the quartz on the left, or pearly, like the gypsum on the right.
Words that can be used to describe a mineral’s luster? *Glassy *Shiny *Dull *Greasy
Other terms that might be used include greasy, dull, and earthy. Can you tell which of these has an earthy luster and which has a vitreous luster? Vitreous Earthy
Earth Science 2nd, 3rd, 4th Monday, October 4, 2010 + Collected homework assignment from Friday, October 1, 2010 * Read 9.2 {pages 163-169} * Outline section 9.2 + Began class notes regarding “Properties used to Identify Minerals” + Read or reread section 9.2, then answer Critical Thinking questions 1-5 and Application 1-4 on page 171.