Clue 1 - Minerals - Station 7     Characteristic properties:  Hardness and streak
Wednesday, May 09, 2012
8:39 AM
Station 7:  Hardness and streak 
How minerals behave when you scratch them
Mohs hardness
_____________________
Diamonds
_____________________
The glaze on a tile
The tile
Hardhess kit
Streak and hardness are two properties of minerals that can be observed when you drag these minerals along another surface, like the surface of another mineral, glass or an unglazed tille.
Observe the streak and hardness of each of the minerals at this station and fill in the table below.
Determine streak and note in table
Drag the mineral specimen on the unglazed side of the porcelain tile.  See if it makes a mark of any color.   If it makes a mark, note the color of the mark on the table below.  The color of the powdered material left on the tile is the streak.
Determine hardness relative to glass and note in table
Drag the mineral specimen on the glass and test whether it is able to scratech glass.
Mineral
Color of streak
Ability to scratch glass
Quartz  
Orthoclase feldspar
Corundum
Limonite
Hematite
Pyrite
Pencil
Which minerals have a streak?
Metallic
Nonmetallic
How can you distinguish hematite from pyrite?
Hematite has a reddish streak
Hematite is always red
Hematite is …
How can you distinguish quartz from feldspar?
The specimen that is feldspar will scratch glass
The specimen that is quartzwill scratch glass