Mineral Identification By Christine You and Quique Fox 7A
Minerals can be identified by:
1. Their physical properties (for example: color, etc.)
2. Their hardness
3. Luster
4. Specific gravity
5. Streak
6. Whether they have cleavage or fracture
7. Their unique properties


Their physical properties such as color can help identify minerals. Sometimes just by looking at their physical properties doesn't help. Since pyrite and gold are the same color, sometimes people confuses which is which.
mohs_scale.jpg
Mohs Scale


The hardness of a mineral is how easily a mineral can be scratched. Friedrich Mohs came up with the Mohs scale. It's a list of ten minerals used to compare their hardness of these ten minerals. The mineral that has a hardness value of one is the softest (talc) and the mineral that ha s a hardness value of ten is the hardest (diamond).

fluorite.jpg
Fluorite
Luster
is the way a mineral reflects light. There's metallic and nonmetallic luster. Minerals that shine have metallic luster and minerals that do not shine have nonmetallic luster. Graphite shines meaning it's a mineral with metallic luster. Halite, quartz, and fluorite are minerals of glassy luster (a different term for nonmetallic luster).


Specific gravity of a mineral is the ratio of its weight compared with the weight of an equal volume of water. For example, gold is about 19 times heavier than water and pyrite's 5 times heavier than water which means pyrite's much lighter than gold.


white_streak_plate.jpg
Streak Plate
Streak
is the color of a mineral in powdered form. Streak plates are used to see what a mineral's streak is. But it can only be used for minerals softer than a streak plate. The streak of some minerals aren't the same as the color. But some are. For example, pyrite is golden but its streak is greenish-black or brownish-black and gold is golden and its streak is gold. It's one way how we know if this mineral is pyrite or gold.
Quartz.jpg
Quartz






Minerals have
cleavage when they break along smooth, flat surfaces. For example, halite breaks along smooth, flat surfaces. Therefore, it has cleavage. Minerals have fracture when they break with uneven, rough or jagged surfaces. Quartz breaks with uneven, jagged surfaces so therefore, it has fracture.


Some minerals can be identified by their unique properties. Calcite can be identified easily because if we add hydrochloic acid on it, it fizzes. Azurite has a striking blue color. Because magnetite is magnetic, you can easily identified it. Fluorite glows under ultraviolet light. Halite tastes salty if you taste it (tasting minerals must been done properly).


Work cited
Information Sources

http://ezinearticles.com/?Properties-of-Minerals&id=1136998
http://facweb.bhc.edu/academics/science/harwoodr/Geol101/Labs/Minerals/
http://geology.about.com/od/mineral_ident/ss/beginminident_7.htm
http://www.spacesciencegroup.org/sootw/Default.asp?Theme=earthscience&pagename=specialproperties
Earth Science Textbook
Image Sources
http://depthome.brooklyn.cuny.edu/geology/core332/images/streak.jpg
http://stloe.most.go.th/html/lo_index/LOcanada2/203/images/2_3_4en.jpg
http://upload.wikimedia.org/wikipedia/commons/a/ab/USDA_Mineral_Quartz_Crystal_93c3951.jpg