What is the chemical composition of nepheline syenite?

Nepheline syenite

Is nepheline syenite a mineral?

Nepheline is a feldspathoid, a solid-solution mineral, that does not coexist with quartz; rather, nepheline would react with quartz to produce alkali feldspar.

What is the composition of syenite?

Syenite is intrusive igneous rock that basically composed of an alkali feldspar and a ferromagnesian mineral. A unique group of alkali syenites is characterized by the presence of a feldspathoid mineral inclusive of nepheline, leucite, cancrinite, or sodalite (see nepheline syenite).

What kind of mineral is nepheline?

feldspathoid mineral
Nepheline is an important feldspathoid mineral. It is white, grey or yellow in colour with a vitreous lustre and a poor cleavage. The name Nepheline comes from the Greek word nephele, which means “cloud,” because it becomes strongly clouded when put in strong acid. Nepheline only forms in silica-poor rocks.

Is nepheline present in granite?

Nepheline syenite, medium- to coarse-grained intrusive igneous rock, a member of the alkali-syenite group (see syenite) that consists largely of feldspar and nepheline. It is always considerably poorer in silica and richer in alkalies than granite.

What minerals are in syenite?

Syenite, any of a class of intrusive igneous rocks essentially composed of an alkali feldspar and a ferromagnesian mineral. A special group of alkali syenites is characterized by the presence of a feldspathoid mineral such as nepheline, leucite, cancrinite, or sodalite (see nepheline syenite).

Where is nepheline syenite found?

Nepheline Syenite is an anhydrous sodium potassium alumino silicate. Although feldspar-like in its chemistry, mineralogically it is an igneous rock combination of nepheline, microcline, albite and minor minerals like mica, hornblende and magnetite. It is found in Canada, India, Norway and USSR.

What are the different types of syenite?

The Center I intrusion includes Eastern gabbro, Western gabbro, amphibole–quartz syenite, iron-rich augite syenite, monzodiorite, and mafic volcanic and subvolcanic rocks. Center II includes amphibole–nepheline syenite and alkaline gabbro. Center III includes quartz syenite and amphibole–quartz syenite (Fig. 4.14).

What is the hardness of syenite?

This mineral raw material therefore contains no crystalline quartz; it is inert and is characterized in addition by a high degree of hardness (Mohs hardness 6.5).

What is Zeolite formula?

Zeolites are microporous, three dimensional crystalline solid of aluminium silicate. The chemical formula of zeolites is Na2Al2Si2O8. xH2O. Zeolites have small openings of fixed size in them which allow small molecules to pass through them easily but larger molecules cannot pass through them.

How do you identify a nepheline?

Nepheline is found in compact, granular aggregates, and can be white, yellow, gray, green, or reddish. Its hardness on the Mohs scale is 5.5–6, and its specific gravity 2.60–2.65. It is often translucent with a greasy luster.

Is nepheline syenite toxic?

Acute Toxicity Values: No acute toxicity data is available for product. This product is not expected to present an environmental hazard. ISECTION 13: DISPOSAL CONSIDERATIONS. Waste Disposal Method: Nepheline Syenite is not classified as a hazardous waste under US EPA RCRA regulations.

Where can you find nepheline syenite in rocks?

It is found in the rocks, nepheline-syenite and phonolite. Nepheline syenite is now being used in substantial amounts by the ceramic industries.

How is nepheline syenite gneiss different from granite?

Different from granite, zircon is rare and, if present, it is as xenocrysts. On the other hand, nepheline syenite gneiss contains abundant and large zircon crystals. Silica-undersaturated igneous rocks typically are formed by low degrees of partial melting in the Earth’s mantle. Carbon dioxide may dominate over water in source regions.

Which is the extrusive equivalent of a nepheline syenite?

Phonolite is the fine-grained extrusive equivalent. Nepheline syenites are silica-undersaturated and some are peralkaline (terms discussed in igneous rock ).

What kind of minerals are found in nepheline?

Composition: Molecular Weight = 146.08 gm Potassium 6.69 % K 8.06 % K2O Sodium 11.80 % Na 15.91 % Na2O Aluminum 18.47 % Al 34.90 % Al2O3 Silicon 19.23 % Si 41.13 % SiO2 Oxygen 43.81 % O 100.00 % 100.00 % = TOTAL OXIDE Empirical Formula: Na0.75K0.25Al(SiO4) Environment: Silica-poor igneous rocks.