Is pumice a basaltic?

Is pumice a basaltic?

It is commonly but not exclusively of silicic or felsic to intermediate in composition (e.g., rhyolitic, dacitic, andesite, pantellerite, phonolite, trachyte), but basaltic and other compositions are known. Pumice is commonly pale in color, ranging from white, cream, blue or grey, to green-brown or black.

Is pumice a granitic rock?

Hi Peter, these three rocks that you asked about are all igneous rocks that form from volcanic magma. The reason that pumice and scoria have holes in the rock and granite does not is due to the way they form. This rock is a piece of granite, which is an intrusive igneous rock.

Is pumice a vesicular basalt?

Scoria and pumice take vesiculation to the extreme. Scoria is an extremely vesicular basaltic lava with very small (< 1mm) vesicles.

How is basalt and pumice different?

Both pumice and obsidian are glassy (amorphous,non-crystalline, and having non-discernable mineral proportions). Basalts belong to extrusive-fine igneous rock group. Basalts have feldpars, highly mafic minerals, and few dark minerals. Basalts are fine (granular) extrusive igneous rocks.

What kind of igneous rocks are pumice and basalt?

Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. Some cool so quickly that they form an amorphous glass. These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.

What kind of rock is basalt?

volcanic rock
Basalt is a hard, black volcanic rock. Basalt is the most common rock type in the Earth’s crust. Depending on how it is erupted, basalt can be hard and massive (Figure 1) or crumbly and full of bubbles (Figure 2).

What is the characteristics of pumice?

Pumice is an unusually light rock due to the many bubbles inside it, Figure 3(b). Pumice has an average porosity of 90% and initially floats on water. Pumice varies in density according to the thickness of the solid material between the bubbles; many samples float in water.

What is pumice made of?

Pumice is formed when volcanoes erupt explosively. It comes from the same kind of magma which would form granite or rhyolite, that is, a magma that contains lots of silica (quartz). Magma with lots of silica is usually thick and sticky.

What rock type is basalt?

Basalt is a hard, black volcanic rock. Basalt is the most common rock type in the Earth’s crust. Depending on how it is erupted, basalt can be hard and massive (Figure 1) or crumbly and full of bubbles (Figure 2).

What do basalt pumice and obsidian have in common?

Both pumice and obsidian are glassy (amorphous,non-crystalline, and having non-discernable mineral proportions). Basalts belong to extrusive-fine igneous rock group. Basalts have feldpars, highly mafic minerals, and few dark minerals.

Is pumice extrusive or intrusive?

extrusive volcanic rock
Pumice is a type of extrusive volcanic rock, produced when lava with a very high content of water and gases is discharged from a volcano.

What composition is pumice?

The chemical properties of pumice will vary from deposit to deposit, but essentially, pumice is primarily Silicon Dioxide (Amorphous Aluminum Silicate), some Aluminum Oxide, and trace amounts of other oxides.

Is basalt a granite?

Basalt and granite are similar in the they are both igneous, silicate rocks and common on Earth. They also have numerous differences. Basalt is extrusive, mafic, and common throughout the Solar System whereas granite is intrusive, felsic, and common only on Earth.

What types of rocks are basalt and granite?

Igneous rocks
Igneous rocks (Granites). Igneous rocks are formed by the crystallisation of a magma. The difference between granites and basalts is in silica content and their rates of cooling. A basalt is about 53% SiO2, whereas granite is 73%.