rocks Flashcards
Minerals def
naturally occuring inoganic solid with a specific composition and crystal structure
what does naturally occuring mean?
NOT HUMAN MADE
what is an inorganic solid?
made from non-living materials
what does specific composition mean?
made from various elements such as oxygen, silicon etc
What are all minerals composed of?
one or more elements
What does it mean to have distinct crystal structure?
- the mineral shape is determined by how the atoms are arranged
- the minerals atoms are arranged in a specific pattern that repats itself over and over
- the longer the mineral cools and hardens the larger the crystals become
what shape do the atoms make in all minerals?
a tetrahedron
a mineral has its specific properties because of what?
because of the internal arrangement of its atoms
What is responsible for a crystal structure’s chemical and physical properties?
the arrangment of the mineral’s atoms
All minerals are rocks but…
not all rocks are minerals
What are the most abundant elements that make up the earth’s crust?
oxygen and silicon
how are minerals identified?
using:
1.color
2.hardeness
3.luster
4. streak
5. breakage
6.specific gravity
7. fracture
how does someone identify a mineral using color?
by observing the actual color of the mineral
why is using color not a great way to indentify a mineral?
because some minerals have the same color (gold and pyrite)
how does someone indentify a mineral based on hardness?
by finding the minerals hardness relative to other known objects
what scale is used to measure hardness of minerals?
Moh’s hardness scale
How does someone identify a mineral using streak?
by observing the color left on a streak plate when the mineral is rubbed on it.
how does someone identify a mineral using luster
by observing if the mineral is metallic (shiny like a metal) or non metallic (not shiny)
how does someone identify a mineral using breakag
by observing if it has cleavage (flat breakage)
how does someone identify a mineral using fracture?
by observing if the mineral has an uneven breakage
How does someone identify a mineral based on specific gravity?
by finding the density if a mineral
define specific properties
some minerals have specific porperties that help identification
Examples of specific properties
- double refraction - splits light to show a double image
- acid soluble - dissolves in acid
- magnetic - able to attract metal by magnetism
When does igneous rock form?
form when molten magma or lava cools and hardens
define lava
MAGMA THAT COOLS ABOVE GOUND
Describe volcanic rocks
they are extrusive
they form above the surface
they cool quickly they have small crystals
define extrusive
LEFT GROUND
examples of volcanic rock
basalt, prumice, rhyolite and obsidian
Define magmA
LIQUID ROCK BELOW EARTHS CRUST
Describe plutonic rocks
They are intrusive
form below surface
they cool slowly
they have large crystals