Chapter 5

Vesicular Texture

A spongy-looking rock; lava whose gas bubbles do not escape.

Porphyritic Texture

An igneous texture consisting of large crystals embedded in a matrix of much smaller crystals.

Intrusive Rock

Igneous rock that forms when magma hardens beneath Earth's surface.

Lava

Is magma that flows out onto Earth's surface.

Granitic Rocks

Light-colored, high silica content, and contain mostly quartz, potassium feldspar, and plagioclase feldspar.

Bowen's Reaction Series

Minerals form in predictable patterns in a process.

Fractional Crystallization

Process in which different minerals crystallize from magma at different temperatures removing elements from magma.

Partial Melting

Process in which different minerals melt into magma at different temperatures, changing its composition.

Kimberlites

Rare, ultramafic rock that can contain diamonds and other minerals formed only under very high pressures.

Igneous Rock

Rocks form when lava or magma cools and minerals crystallize.

Texture

The size, shape, and distribution of the crystals or grains that make up a rock.

Pematities

Vein deposits of extremely large-grained minerals that can contain rare ores such as Lithium and Beryllium.

Basaltic Rocks

dark colored, have lower silica contents, and contain mostly plagioclase and pyroxene

Extrusive Rocks

rocks formed from molten lava that hardens on the earth's surface.