A
A hard material that composes the earth’s crust
rocks
Fine-grained rock formed when magma cools and hardens at the earth’s surface
extrusive igneous rocks
A shiny black igneous rock that resembles a glass
obsidian
A light-colored rock that contains at least three different kinds of minerals—mica, quartz, and feldspar
granite
three broad categories of rocks
igneous, sedimentary, metamorphic
A material that comes from decayed plants and is mined throughout the world for heating and industrial purposes
coal
A rock formed from mud or clay that consists of much smaller particles than sand; can be easily broken and ground up for use in making bricks.
shale
A weather-resistant, waterproof rock that begins as a shale
slate
A type of sediment formed when minerals in a rock are dissolved by water and carried elsewhere, where they may later crystallize or settle out of the solution.
chemical sediments
what do rocks need to go through in order to transform
extreme heat and pressure
the individual substances that makes up rocks
minerals
A kind of rock made up of layers like the leaves (pages) of a book
foliated rocks
A rock made of round pebbles embedded in hardened sand or clay
conglomerate
The most common type of organic sedimentary rock; when subjected to heat and pressure, it will turn into a marble
limestone
hot, fluid rock
magma
A rock known as the “changed ones” for it is formed by the metamorphism of an igneous or a sedimentary rock
metamorphic rocks
A word which means “forced into or between"; coarse-grained rock formed when magma cools and hardens still underground
intrusive
A rough, crumbly rock which consists of particles of quartz sand that have been fused together into rock
sandstone
A rock that is used in construction materials such as plaster of Paris and plaster board.
gypsum
known as rock salt
halite
A rock that is formed from sediments that have been pressed together into solid rock
sedimentary rocks
A rock formed from runny lava and often solidifies in vast mounds or sheets
basalt
The most beautiful and most widely used unfoliated rock; hardened by extreme heat and pressure within the earth.
marble
A kind of sediment made of dead plants, shells, or animal skeleton
organic sediment
any trace left in rock by a plant or animal
fossil