Common rocks
Other rocks
Other rocks
Other rocks
Other rocks
100
Rock that in its molten form (as magma) issues from volcanos.
What is a lava rock?
100
Rock consisting of angular fragments cemented together.
What is breccia?
100
A plutonic rock composed largely of calcic plagioclase.
What is anorthosite?
100
A dark-gray to black, medium-grained igneous rock consisting mainly of labradorite and pyroxene.
What is diabase?
100
A very hard, granular, crystalline, igneous rock consisting mainly of quartz, mica, and feldspar and often used as a building stone.
What is granite?
200
This is from Triassic Utah. It has a sequence of siltstones and limestones.
What is sedimentary rock?
200
A speckled, coarse-grained igneous rock consisting essentially of plagioclase, feldspar, and hornblende or other mafic minerals.
What is diorite?
200
A volcanic rock resembling andesite but containing free quartz.
What is dacite?
200
A metamorphic rock with a banded or foliated structure, typically coarse-grained and consisting mainly of feldspar, quartz, and mica.
What is gneiss?
200
A dark, coarse-grained plutonic rock of crystalline texture, consisting mainly of pyroxene, plagioclase feldspar, and often olivine.
What is gabbro?
300
A dark, fine-grained volcanic rock that sometimes displays a columnar structure.
What is basalt?
300
A hard, dark, glasslike volcanic rock formed by the rapid solidification of lava without crystallization.
What is obsidian?
300
A hard gray rock consisting of nearly pure chert, occurring chiefly as nodules in chalk.
What is flint?
300
A coarse-grained sedimentary rock composed of rounded fragments (> 2 mm) within a matrix of finer grained material.
What is conglomerate?
300
A dense, coarse-grained plutonic rock containing a large amount of olivine, believed to be the main constituent of the earth's mantle.
What is peridotite?
400
Rocks that have become changed by intense heat or pressure while forming.
What is metamorphic rock?
400
A hard sedimentary rock, composed mainly of calcium carbonate or dolomite, used as building material and in the making of cement.
What is limestone?
400
A hard crystalline metamorphic form of limestone, typically white with mottlings or streaks of color, that is capable of taking a polish and is used in sculpture and architecture.
What is marble?
400
Denoting rocks composed of broken pieces of older rocks.
What is clastic?
400
A very light and porous volcanic rock formed when a gas-rich froth of glassy lava solidifies rapidly.
What is pumice?
500
Form when hot, molten rock crystallizes and solidifies.
What is igneous rock?
500
An idealized cycle of processes undergone by rocks in the earth's crust, involving igneous intrusion, uplift, erosion, transportation, deposition as sedimentary rock, metamorphism, remelting, and further igneous intrusion.
What is the rock cycle?
500
A hard, dark, opaque rock composed of silica (chalcedony) with an amorphous or microscopically fine-grained texture. It occurs as nodules (flint) or, less often, in massive beds.
What is chert?
500
Rock consisting of dolomite.
What is dolostone rock?
500
A coarsely crystalline granite or other igneous rock with crystals several centimeters to several meters in length.
What is pegmatite?