Pyroxene vs Amphibole: Difference and Comparison

Several kinds of rocks consist of minerals that had used for several purposes. Metamorphic contains different minerals, and those rocks had used for suitable purposes. Pyroxene and Amphibole are minerals that contain in metamorphic rocks.  

Key Takeaways

1. Pyroxene is a group of dark-colored, silicate minerals that crystallize in a single chain of tetrahedrons.
2. Amphibole is a group of dark-coloured, silicate minerals that crystallize in a double chain of tetrahedrons.
3. Pyroxene and amphibole are common rock-forming minerals in igneous and metamorphic rocks but have different crystal structures and chemical compositions.

Pyroxene vs Amphibole  

Pyroxene is a type of mineral that can be used in the formation of rocks. Metamorphic rocks contain pyroxene minerals. The abbreviation used for pyroxene is ‘Px.’ Amphibole is a mineral that can be found in igneous rocks. There are two types of crystal structures in amphiboles. Amphibole stones can be used in the construction of roads.

Pyroxene is a mineral found in metamorphic rocks. The pyroxene minerals had found in igneous and metamorphic rocks. Pyroxene is a large class of rocks that forms silicate minerals and contains calcium, magnesium, and iron.

Pyroxene had mainly materialized as prismatic crystals. Pyroxene had abbreviated as Px, where a group of minerals forming in an igneous and metamorphic rock.  

Amphibole is a group of inosilicate minerals that materialize in prisms and needle-like crystals. Amphibole contains a chain of SiO4 tetrahedra molecules.

Amphibole consists of iron ions and magnesium ions in the structure of the Amphibole crystals. Amphibole had available in different types of colours. 

Comparison Table

Parameters of Comparison	Pyroxene	Amphibole
Meaning	Pyroxene is the inosilicate minerals that form in metamorphic rocks.	Amphibole is a group of inosilicate minerals contains in igneous and metamorphic rocks.
Minerals	Pyroxene obtains silicate minerals, calcium, iron ions and magnesium ions.	Amphibole consists of minerals like aluminium silicate, sodium ions, iron ions, magnesium and tetrahedra ions.
Structure	Pyroxene accommodates Octahedral layers that contain marked cations like M1 and M2.	Amphibole appears in two different crystal structure. Monoclinic and Orthorhombic are the structures of Amphibole.
Colours	Depending on the chemical process, the Pyroxene can turn from dark green to black colour, turn into apple green and from lilac to colourless.	Depending on the chemical compositions, Amphibole can turn colourless to green, white, brown, black, blue or lavender.
Properties	Pyroxene consists of 5-6 of solidity, specific gravity up to 3.2-3.9, cleavage planes. Have crystal structure and Lustre.	Amphibole consists of 5-6 of solidity, specific gravity up to 2.9-3.2. Elongate habit and two directions of cleavage are the main properties.

What is Pyroxene?  

Pyroxene is an inosilicate mineral that forms on igneous and metamorphic rocks. Pyroxene is a large class of rocks that form silicate minerals and contains calcium, magnesium, and iron.

Pyroxene had mainly materialized as prismatic crystals. Pyroxene had abbreviated as Px, where a group of minerals forms in Igneous, metamorphic rock.

The Chemical formula of Pyroxene is XY(Si, Al)2SO2. Where X constitutes calcium, sodium, magnesium, iron (II), lithium, and manganese, Y constitutes smaller-size ions such as chromium, magnesium, cobalt, iron (II), aluminum, manganese, scandium, titanium, vanadium, and iron.  

There may exist so many kinds of pyroxenes, such as magnesium-iron pyroxenes, calcium-sodium pyroxenes, sodium pyroxenes, calcium pyroxenes, and lithium pyroxenes. Pyroxene accommodates Octahedral layers where those layers had marked as M1 and M2.

Depending on the chemical process, the Pyroxene can turn from dark green to black colour, turn into apple green, and from lilac to colourless. Properties of Pyroxene had it consists of 5-6 of solidity, specific gravity up to 3.2 to 3.9, cleavage planes, Lustre, and crystal structure.

The minor and secondary compositions of Pyroxene are used as the crushed stone and dimension stone.  

What is Amphibole?  

Amphibole is one of the inosilicate mineral rocks located on igneous and metamorphic rocks. An amphibole is a group of inosilicate minerals that materialize in prisms and needle-like crystals.

Amphibole contains a chain of (SiO)4 tetrahedra molecules. (X)7Si8O22(OH)2 is the main chemical formula of the Amphibole, where X represents iron, magnesium, and calcium.

Amphibole consists of minerals like aluminum silicate, sodium ions, iron ions, magnesium, and tetrahedra ions. (X)7Si8O22(OH)2 is the main chemical formula of the Amphibole, where X represents iron, magnesium, and calcium.   

Amphibole appears in two different crystal structures. Monoclinic and Orthorhombic are the structures of Amphibole. Depending on the chemical composition, Amphibole can turn colourless to green, white, brown, black, blue, or lavender.

Properties of the Amphibole are 5 to 6 of hardness, 2.9 to 3.2 of specific gravity, two directions of cleavage planes such intersects 59 degrees and 120 degrees, and broadened habit.

Amphibole rocks had used as paving stones and slightly facing on the buildings as interior parts or exterior parts. An Amphibole had mainly used as crushed stones that helped in constructing roads and railroads.  

Main Differences Between Pyroxene and Amphibole  

1. Pyroxene is an inosilicate mineral used on rocks, whereas Amphibole is also an inosilicate mineral that forms on igneous and metamorphic rocks.  
2. Pyroxene can find in prismatic crystals, whereas Amphibole can appear in prisms and needle-like crystals.  
3. Pyroxene accommodates Octahedral layers where Amphibole appears Monoclinic and Orthorhombic in structure.  
4. The Chemical formula of Pyroxene is XY(Si, Al)2 SO2, where X and Y represent various ions. On the other way out, (X)7Si8O22(OH)2 is the main chemical formula of the Amphibole, where X represents iron, magnesium, and calcium. 
5. Pyroxene can turn from dark green to black colour, turn into apple green, and from lilac to colourless, whereas Amphibole can turn colourless to green, white, brown, black, blue, or lavender.  
6. Pyroxene contains a single chain of tetrahedra ions. On the other hand, Amphibole consists of a double chain of tetrahedra ions.  

References

1. https://www.sciencedirect.com/science/article/pii/001670378190065X
2. https://link.springer.com/content/pdf/10.1007/BF00371882.pdf
3. https://link.springer.com/content/pdf/10.1007/BF00636515.pdf