Transcript Minerals – Earth`s Jewels

Minerals – Earth’s Jewels
SWBAT identify the difference between
a mineral and a rock; describe the
properties that are used to identify
minerals
What is a mineral?
• Minerals
– inorganic, solid materials found in nature.
• What does inorganic mean?
– It was not formed by plants or animals
• Rock
– made up of two or more minerals.
What is a mineral?
• How do minerals form?
– Minerals form from melted rock material,
called magma, that cools
• Precipitation
– Water drops out minerals that it cannot hold
Properties of Minerals
• Crystals
– Crystals have an orderly pattern of atoms,
arranged in a repeating pattern
Properties of Minerals
• Cleavage and fracture
– How to a mineral breaks
• Cleavage
– Minerals break into smooth planes
• Fracture
– Minerals break roughly with jagged or rough
edges
Properties of Minerals
• Color
– This is the least reliable property of minerals.
Colors can be misleading (gold and pyrite),
and some minerals come in many different
colors.
Properties of Minerals
• Streak
– Scrape a mineral across an unglazed
porcelain tile and the color it leaves is its
streak. Streak does not always match the
color
• Luster
– Describes how a mineral reflects light
– Shiny, dull, pearly, etc.
Properties of Minerals
• Hardness
– Mohs scale gives the hardness of each
mineral
– What it can be scratched by shows how hard
it is
Properties of Minerals
• Specific Gravity
– Similar to density
– Ratio of weight of the sample to an equal
volume of water
Properties of Minerals
• Other properties
– Magnetism
– Smell
– Reaction to chemicals
– Visual distortion
– Taste
Common Minerals
• What do we call the common minerals that
make up rocks?
– Rock forming minerals, which are mostly
silicates (they contain silicon and oxygen)
• Gem
– Minerals that are rare and can be cut and
polished to give them a beautiful appearance
• Ore
– Minerals that are mined for a profit