How to classify amphibole?
How to classify amphibole?
NEW SCHEMES FOR THE CLASSIFICATION OF AMPHIBOLES First, amphiboles are divided into two classes according to the dominant W species: (OH,F,Cl)-dominant amphiboles; O-dominant amphiboles.
Which is an amphibole?
Amphibole (/ˈæmfəboʊl/) is a group of inosilicate minerals, forming prism or needlelike crystals, composed of double chain SiO. 4. tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures.
How many different amphiboles are there?
There are 5 major groups of amphiboles leading to 76 chemically defined end-member amphibole compositions according to the British mineralogist Bernard E. Leake.
What is the most common amphibole group mineral?
Introduction
| Mineral group | Asbestos variety | Nominal chemical formulaea |
|---|---|---|
| Amphibolec | Amosite | (Fe2+Mg)7Si8O22(OH)2 |
| Amphibole | Crocidolite | Na2Fe3+(Fe2+Mg)3Si8O22(OH)2 |
| Amphibole | Anthophyllite | Mg7Si8O22(OH)2 |
| Amphibole | Actinolite | Ca2Fe42+MgSi8O22(OH)2 |
What are pyroxenes and amphiboles explain?
The difference between Pyroxene and Amphibole is that Pyroxene is a group of inosilicate minerals that forms in metamorphic rocks. In contrast, Amphibole is an inosilicate mineral that forms prisms or needlelike crystals. Amphibole is a group of inosilicate minerals that materialize in prisms and needle-like crystals.
What are amphiboles for?
It is used as paving stones and as a veneer or facing on buildings (both for interior and exterior use). It is also used as crushed stone for the usual crushed stone applications such as road and railroad bed construction. In this application it is used locally, near the source of the amphibolite.
What are amphiboles made from?
The amphiboles typically occur with plagioclase feldspar, quartz, and biotite, as well as with chlorite and oxide minerals. In magnesium-rich rocks, tremolite, anthophyllite, and hornblende may exist together. Gedrite and cummingtonite coexist with garnet in rocks enriched in aluminum and iron.
What is the hardness of amphiboles?
Long prismatic, acicular, or fibrous crystal habit, Mohs hardness between 5 and 6, and two directions of cleavage intersecting at approximately 56° and 124° generally suffice to identify amphiboles in hand specimens. The specific gravity values of amphiboles range from about 2.9 to 3.6.
How do you identify olivine?
Olivine is usually green in color but can also be yellow-green, greenish yellow, or brown. It is transparent to translucent with a glassy luster and a hardness between 6.5 and 7.0. It is the only common igneous mineral with these properties. The properties of olivine are summarized in the table.
Where are Amphiboles found?
igneous rocks
Amphiboles are found principally in metamorphic and igneous rocks. They occur in many metamorphic rocks, especially those derived from mafic igneous rocks (those containing dark-coloured ferromagnesian minerals) and siliceous dolomites.
What kind of structure does an amphibole have?
Amphiboles have hydroxyl groups in their structure and are considered to be hydrous silicates that are stable only in hydrous environments where water can be incorporated into the structure as (OH) -.
What was the IMA classification of Leake amphiboles?
Leake (1968) presented a classification for calcic amphiboles, and this was expanded into the International Mineralogical Association (IMA) classification of Leake (1978), henceforth referred to as IMA1978.
Who was the first to classify calcic amphiboles?
Leake (1968) presented a classification for calcic amphiboles, and this was expanded into the International Mineralogical Association (IMA) classification of Leake (1978), henceforth referred to as IMA1978. An IMA Subcommittee on Amphibole Classification was formed, and Leake et al.
How are amphiboles classified as a supergroup of minerals?
The International Mineralogical Association currently classifies amphiboles as a mineral supergroup, within which are two groups and several subgroups. Photomicrographs of a thin section containing an amphibole crystal; under cross-polarized light on the left, and plane-polarized light on the right.
