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Which rocks has two different size grains of the same mineral?

Pegmatite is a type of igneous rock that can have two different grain sizes of the same mineral present. This is due to the slow cooling process of the magma, allowing for the growth of large crystals (phenocrysts) within a finer-grained matrix.


Does a porphyritic texture include two different sizes of mineral grains?

Yes, a porphyritic texture consists of two distinct sizes of mineral grains - larger crystals called phenocrysts surrounded by a finer-grained matrix called groundmass. This texture typically forms in magmas that experience two stages of cooling, resulting in the different sizes of crystals.


Is pumice a metamorphic rock?

No, pumice is not a metamorphic rock. It is actually a type of igneous rock that forms from volcanic eruptions when frothy lava cools rapidly and traps gas bubbles inside, resulting in its characteristic porous texture. Metamorphic rocks are formed through the transformation of existing rocks under heat and pressure.


What texture is igneous?

igneous is the texture of igneous rocks. The texture of igneous rocks is defined by 3 ways: a) Crystallinity- it expresses the degree of formation of crystals in an igneous rock. the texture of an igneous rock may be Holocyrstalline (Completely characterised by crystals, Hemicrystalline (partially having crystals) and holocrystalline (no crystals). b) Granularity- it is the size of the grains. it may be equigranular (when mineral grains are equal in size) or inequigranular (when mineral grains are not equal in size). c) shape of crystals- The shape of crystals may be Euhedral (When all crystals are of same shape), Subhedral (when they are partially similar in shape), Anhedral (when they are completely different in shape).


Which rock has large mineral grains granite obsidian basalt or pumice?

Granite has large mineral grains compared to obsidian, basalt, and pumice. Granite is an intrusive igneous rock that forms deep within the Earth's crust, allowing for the growth of large mineral crystals due to slow cooling. Obsidian, basalt, and pumice are extrusive igneous rocks that cool quickly at the Earth's surface, resulting in smaller mineral grains or a glassy texture.

Related Questions

Which rocks has two different size grains of the same mineral?

Pegmatite is a type of igneous rock that can have two different grain sizes of the same mineral present. This is due to the slow cooling process of the magma, allowing for the growth of large crystals (phenocrysts) within a finer-grained matrix.


Igneous rock that forms deep inside the earth and has large mineral grains is called?

Intrusive igneous rock.


Does a porphyritic texture include two different sizes of mineral grains?

Yes, a porphyritic texture consists of two distinct sizes of mineral grains - larger crystals called phenocrysts surrounded by a finer-grained matrix called groundmass. This texture typically forms in magmas that experience two stages of cooling, resulting in the different sizes of crystals.


Is pumice a metamorphic rock?

No, pumice is not a metamorphic rock. It is actually a type of igneous rock that forms from volcanic eruptions when frothy lava cools rapidly and traps gas bubbles inside, resulting in its characteristic porous texture. Metamorphic rocks are formed through the transformation of existing rocks under heat and pressure.


What texture is igneous?

igneous is the texture of igneous rocks. The texture of igneous rocks is defined by 3 ways: a) Crystallinity- it expresses the degree of formation of crystals in an igneous rock. the texture of an igneous rock may be Holocyrstalline (Completely characterised by crystals, Hemicrystalline (partially having crystals) and holocrystalline (no crystals). b) Granularity- it is the size of the grains. it may be equigranular (when mineral grains are equal in size) or inequigranular (when mineral grains are not equal in size). c) shape of crystals- The shape of crystals may be Euhedral (When all crystals are of same shape), Subhedral (when they are partially similar in shape), Anhedral (when they are completely different in shape).


Why do igneous rocks that have the same composition sometimes have different sizes of mineral grains?

This is as a result of difference in the rate of cooling of the Igneous rocks.


In a porphyritic volcanic rock which mineral grains are the last to crystallize In a porphyritic volcanic rock which mineral grains are the last to crystallize?

In a porphyritic volcanic rock, the mineral grains that are last to crystallize are typically the finer-grained groundmass minerals, which may include plagioclase, pyroxene, or quartz, depending on the specific composition of the rock. The larger, more visible crystals, known as phenocrysts, form first during the initial stages of cooling, while the smaller crystals in the groundmass crystallize later as the magma continues to cool and solidify. This texture reflects the complex cooling history of the magma, with rapid cooling at first followed by slower cooling.


What are the different types of grains in a rock?

Grains in a rock can vary in type based on their mineral composition and formation process. Common types of grains include quartz, feldspar, mica, and calcite, each contributing to the rock's overall characteristics. Grains can also differ in size, shape, and texture, leading to classifications such as coarse-grained, fine-grained, or porphyritic. Additionally, the presence of sedimentary, igneous, or metamorphic processes can further influence the type and arrangement of grains within a rock.


Do Glassy igneous rocks form when magma cools too fast for mineral grains to grow?

yes


Why do some igneous rock have bigger mineral grains than others?

This is due to the rate of cooling - a slower rate of cooling results in large mineral grains because the molecules had time to maneuver into a crystalline lattice. A faster rate of cooling results in smaller mineral grains because the molecules were locked into place faster and therefore couldn't form the crystalline lattice structures before getting stuck.


Which rock has large mineral grains granite obsidian basalt or pumice?

Granite has large mineral grains compared to obsidian, basalt, and pumice. Granite is an intrusive igneous rock that forms deep within the Earth's crust, allowing for the growth of large mineral crystals due to slow cooling. Obsidian, basalt, and pumice are extrusive igneous rocks that cool quickly at the Earth's surface, resulting in smaller mineral grains or a glassy texture.


What are the three types of grains of rocks?

The three types of grains in rocks are igneous, sedimentary, and metamorphic grains. Igneous grains form from the cooling and solidification of molten material, sedimentary grains originate from the accumulation of mineral and organic particles, and metamorphic grains result from the alteration of existing rocks under heat and pressure. Each type reflects different geological processes and environments of formation.