Rocks and
Minerals
Vocabulary
Part 1
Core
• Definition: the inner
part of the earth, full
of hot liquid
• Inner core: solid
nickel and iron, solid
because it is under
so much pressure;
800 miles thick;
13,000°F
• Outer core: liquid
nickel and iron; 1,400
miles thick; 11,000°F
Inner Core
Outer Core
Crust
• Definition: the outside
of the earth – the part
we live on – all of the
rocks and minerals
that we know are
found here
• 5 (under the oceans)
- 25 (under the
continents) miles
thick
• 1,600°F at the
deepest parts
Mantle
• Definition: the
layer of earth
below the crust
• 1,000-1,800 miles
thick
• 8,000°F at the
deepest parts
Rock
• Definition: any piece
of solid matter in the
Earth’s crust
• Made up of minerals
• p. 239
Mineral
• Definition: matter that is not plant or
animal
• Rocks are made of these
Gypsum
• p. 239
Pink Chalcedony
Sulfur (yellow)
Geologist
• Definition: a scientist who studies rocks
and minerals
• Includes: volcanoes, earthquakes, specific
rocks, rock formations, identifying new
rocks, how the earth was formed
Appearance
Mesolite
• Definition: the
way something
looks to you
• Includes: color,
luster, size,
crystal structure
• p. 239
Calcite (purple)
on Fluorite
(white/yellow)
Luster
• Definition: the way a rock’s surface reflects
light
• Choices: metallic, nonmetallic, dull, pearly,
glassy, greasy, silky
• p. 240
Greasy
Dull
Glassy (the rock, not
the lichen)
Streak
• Definition: the color
of a mineral in its
powdered form
• BE CAREFUL: a
mineral’s streak is
NOT always the
same as its
appearance
• p. 240-241
Bauxite
Metallic
Gold
• Definition:
minerals with a
shiny
appearance
• Looks like
metal
• p. 240
Azurite
Nonmetallic
• Definition: minerals that allow light to pass
through them, minerals with a dull
appearance
• Includes: dull, pearly, glassy, greasy, silky
• p. 240
Pearly
Silky
Glassy
Hardness
• Definition: the ability to resist being
scratched
• p. 240
• We use the Mohs scale(1-10), created by
Fredrich Mohs (German geologist)
Examples:
1 – fingernail scratches it easily
6 – scratches glass easily
10 – scratches every other mineral (hardest mineral –
diamond)
Layers of the Earth
Crust
Mantle
Core