properties of minerals scientists use characteristics to tell one mineral from another
TRANSCRIPT
Properties of MineralsScientists use
characteristics to tell one mineral from
another
Mineral Properties we will be investigating:
Luster Hardness
StreakTransparency
Luster• Refers to the way light
reflects from the surface of the mineral.
• There are two types of luster, –Metallic: looks like polished metal.
–Nonmetallic: does not look like polished metal.
Pyrite has metallic luster
Quartz has nonmetallic luster
Hardness• Is measured by how easy it is to
scratch. • Geologists order the hardness by…
– Scratched by a fingernail.– Scratched by a penny. – Scratched by a nail. – Scratched by a diamond.
• These are not all of the tools geologists use, but it will work for now when we perform an experiment.
Gypsum is soft, it can be scratched by a
fingernail.
Calcite is soft, but a little harder because it cannot be
scratched by a fingernail, but it can be scratched by a
penny.
Fluorite is harder. It can be scratched by a nail, but not
a penny or fingernail.
Diamonds are the hardest mineral, so it scratches
every mineral.
Transparency• Transparency describes how
much light is able to pass through a mineral
Streak• Red chalk on a chalk board
makes red marks. White chalk makes white marks.
• When some minerals are scratched along a ceramic streak plate they create different colors.
Gold• When gold is
run across a streak plate it makes a yellowish-gold color.
Pyrite or “Fool’s Gold”
• When pyrite is run across a streak plate, it has a black or dark green streak.
• Pyrite is not worth much money, while gold is worth a lot. They look alike, so miners call it fool’s gold.
Hematite• Hematite’s color is
grey, but its streak is red.
• “Hema” means blood.
• The mineral was named hematite because it looked like it was bleeding when it was taken across a streak plate.
Shape
One mineral property we will
not use…
COLOR
A mineral can be many different colors. Below are
samples of Mica.
Many minerals can be the same color. Below are gold colored minerals.
Which one is gold?
The answer…None of them
were real gold.