What is a coarse grained igneous rock called?

Coarse grain varieties (with mineral grains large enough to see without a magnifying glass) are called phaneritic. Granite and gabbro are examples of phaneritic igneous rocks. Fine grained rocks, where the individual grains are too small to see, are called aphanitic. Basalt is an example.

What is a coarse grained igneous rock with no quartz?

Pumice. Pumice does not contain quartz or any other mineral grains. This is due to the rapid cooling process from explosive volcanic magma.

What is an example of an igneous rock with coarse grained texture?

Texture. Figure 4.1. 1: Granite is a classic coarse-grained (phaneritic) intrusive igneous rock.

What type of igneous rocks are coarse and grained?

The name of the igneous rock depends on what minerals are present. If there are lots of light-colored minerals and the rock is coarse grained, it is granite. If there are mostly dark-colored minerals and the rock is fine grained, it is basalt.

Why there are coarse-grained and fine grained texture rocks?

Extrusive or volcanic rocks crystallize from lava at the earth’s surface. The texture of an igneous rock (fine-grained vs coarse-grained) is dependent on the rate of cooling of the melt: slow cooling allows large crystals to form, fast cooling yields small crystals. Volcanic glass is called obsidian.

What is the coarse-grained?

having a coarse texture or grain. indelicate; crude; vulgar; gross: a coarse-grained person with vulgar manners.

Is feldspar igneous sedimentary or metamorphic?

Feldspars occur in most igneous and metamorphic rocks. They are less common in sedimentary rocks as they tend to break down to clay minerals in the weathering environment. Feldspars are broadly divided into two groups: alkali feldspars and plagioclase feldspars.

Why there are coarse grained and fine grained texture rocks?

Is Gabbro coarse or fine grained?

2.4. 1 Mafic Intrusive Igneous Rocks. Gabbro is a mafic intrusive coarse-grained rock with allotriomorphic texture. Gabbros contain low silicon (no Quartz or Alkali feldspar) and essentially of ferromagnesian minerals and Plagioclase feldspar rich in calcium.

Why there are coarse grained and fine-grained texture rocks?

What is the coarse grained?

What makes an intrusive igneous rock look like?

These crystals make a coarse-grained igneous rock called plutonic, or intrusive, igneous rock because the magma was intruded into cracks deep under the earth’s surface. These coarse-grained crystals make the rock look sugary as the flat crystal faces reflect the light in hundreds of little sparkles.

What kind of rock is transparent with thin edges?

Note: Obsidian that is transparent at thin edges and has good conchoidal fracture is probably felsic. FRAGMENTAL TEXTURE–COARSE (CONTAINS LARGE ROCK FRAGMENTS)

Which is an example of a porphyritic igneous rock?

Phenocrysts are the crystals surrounded by the matrix; these are usually large, straight-sided, and glassy minerals unless they have been weathered. Porphyritic is used as an adjective to modify the name of any fine-grained igneous rock that has less than 50% phenocrysts in it. Example: Porphyritic basalt, porphyritic andesite.

What kind of texture does aphanitic rock have?

APHANITIC TEXTURE (FINE-GRAINED) Originates in lava flows (or very shallow intrusions), which cool rapidly Composition Most Common Minerals Rock Name felsic Na-plagioclase, orthoclase, quartz, biotite, amphibole, muscovite rhyolite