Color: what it is
This property shows the outside appearance of the mineral
Color: how it is tested
Test this proberty by looking at the mineral. Minerals can be many colors, and impurities can change a minerals color; therefore this is the least reliable of the tests.
Luster: what it is
This property shows how light reflects off the surface of the mineral. Some examples are glassy, shiny, sparkly, pearly, milky, dull, earthy, or metallic.
Luster: how it is tested
Test this property by holding the mineral up to the light to see how the light reflects off of the mineral.
Streak: what it is
This property shows the true color of the mineral.
Streak: how it is tested
Test this property by rubbing the mineral across an unglazed tile to see the color of its powder.
Hardness: what it is
This property shows how hard or soft the mineral is.
Moh's Hardness scale
Talc would be the softest at 1 and diamond would be the hardest at 10.
Hardness: how it is tested
Test this property by scratching the mineral with other minerals of known hardness or common items such as a fingernail, penny, iron nail, and glass.
Crystal Shape: what is it
This property is the unique 3-D crystal pattern found in a mineral.
No matter what the size of the crystal in a mineral, the shape will always be the same for that specific mineral.
Crystal Shape: how it is tested
Test this property by observing the shape of the crystals when looking at the mineral. Often a microscope is needed to observe this property.