Rocks & Minerals
The hardest known mineral, often found in "pipes"
Diamond
the most commonly used metal for tools throughout history
iron
Formed when molten rock hardens
igneous rock
the space around a magnet where its force acts
magnetic field
This extrusive igneous rock forms on the surface, cools quickly, and has fine grains
basalt
Small pockets or clusters of igneous or metamorphic crystals
Geodes
off topic! which sedimentary rock is formed by living organisms?
chalk
formed when sand and mineral fragments are pressed together
sedimentary rock
the two ends of a magnet
poles
this intrusive igneous rock cools slowly below the surface, forming large crystals
granite
A rock that contains a metal mixed with impurities
Ore
a great conductor of electricity; its alloys include brass and bronze
copper
formed when existing rock changes due to intense heat or pressure
metamorphic rock
the magnetic field surrounding the entire earth
magnetosphere
this chemical sedimentary rock is used for road salt and flavoring
halite
Any preserved trace of a plant or animal found in rock
Fossil
off topic! which metamorphic rock started as shale and has thin, leaflike layers?
slate
75% of Earth's surface is covered by this type of rock
sedimentary rock
the hardest material in the earth's crust
diamond
the sedimentary rock that is the main ingredient in glass
sandstone
The rarest and most beautiful gems, known for their durability
precious stones (gems)
off topic! which type of metamorphic rock has layers resembling the pages of a book?
schist
off topic! What is the most common igneous rock found across the earth?
Basalt
a natural hollow space large enough to enter
cave
this metamorphic rock began as limestone and is known for its beauty and wide use
marble