Granite is a coarse grained igneous rock without Pyroxene.
Obsidian is an igneous rock with no minerals.
The texture would be glassy.
Obsidian
obsidian
Yes. Gabbro is an intrusive igneous rock with visible mineral crystals.
extrusive
Normally the crystals in extrusive igneous rock are small enough as to not be visible without magnification. The exception would be a porphyritic rock that has visible crystals dispersed in a fine-grained matrix. This type of rock represents a partial cooling of magma before expulsion by volcanism.
Tiny crystals in the igneous rock tells you it cooled quickley.
Both are igneous rocks, formed from the cooling and solidification of magma. Granite is a felsic, intrusive igneous rock, with visible well mixed mineral crystals. Basalt is a mafic, extrusive igneous rock, composed of darker mineral crystals, most of which are not distinguishable without the aid of magnification.
Extrusive igneous rock consists of mineral crystals that are not observable with the naked eye. Obsidian is an extrusive igneous rock (volcanic glass) where there technically are no mineral crystals.
Intrusive rock normally has visible crystals. Extrusive igneous rock has small crystals. A black extrusive igneous rock with small crystals could be basalt.
Yes. Gabbro is an intrusive igneous rock with visible mineral crystals.
== Grain size. Most intrusive igneous rocks will have visible crystals. Crystals in most extrusive igneous rocks are not easily visible.
Granite, gabbro, and diorite are a few igneous rocks that forms crystals. Igneous rocks that form visible crystals are intrusive igneous rocks, rocks that form under the earth's surface.
Granite is an igneous rock with visible mineral crystals.
in a cave
extrusive
Porphyrite of any composition, granite, gabbro, diorite. Most intrusive igneous rocks have crystals large enough to see with the naked eye. Another term used to define an igneous rock with large crystals is coarse-grained.
Normally the crystals in extrusive igneous rock are small enough as to not be visible without magnification. The exception would be a porphyritic rock that has visible crystals dispersed in a fine-grained matrix. This type of rock represents a partial cooling of magma before expulsion by volcanism.
The rock would have visible mineral crystals--a phaneritic texture.
Intrusive igneous rock is composed of visible mineral crystals, possessing what is referred to as a phaneritic texture. This is evidence that slow cooling of magma occurred deep underground.