What is syenite used for?

Nepheline syenite from Canada is used to replace feldspar in the manufacture of ceramic and glass products. The feldspar in nepheline syenite may be cryptoperthite or, rarely, a mixture of albite and microcline. Nepheline is sometimes wholly or partly replaced by sodalite or cancrinite.

What is the use of nepheline?

nepheline, also called nephelite, or eleolite, the most common feldspathoid mineral, an aluminosilicate of sodium and potassium [(Na,K)AlSiO4]. It is sometimes used as a substitute for feldspars in the manufacture of glass and ceramics.

What does nepheline look like?

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.

How can you tell nepheline from quartz?

Resembles feldspars but nepheline is uniaxial, lacks good cleavage and twinning, and has a low birefringence. Nepheline is softer than quartz and differs in optic sign. Nepheline occurs in alkali-rich, silicon poor igneous rocks (nepeline syenite, foidite and phonolite).

What does syenite look like?

The texture of syenites, like that of granite, is granular, and these rocks differ from granite only by the absence or scarcity of quartz. The alkali feldspars present may include orthoclase, perthite, albite, or, more rarely, microcline; the ferromagnesian mineral may be biotite, hornblende, or pyroxene.

Is nepheline syenite toxic?

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

What does nepheline syenite do?

Like feldspar, nepheline syenite is used as a flux in tile, sanitary ware, porcelain, vitreous and semi-vitreous bodies. It contributes high alumina without associated free silica in its raw form and fluxes to form silicates with free silica in bodies without contributing free silica itself.

Is quartz a Pleochroic?

Pleochroism: None. Cleavage/fracture: No cleavage, but fractures and healed fractures can be common. Relief and optic sign: Low; uniaxial (+).

Can a feldspathoid occur with quartz in a rock?

(4) They occur principally in igneous rocks, but only in silica-poor rocks, and do not coexist with quartz (SiO2). Feldspathoids react with silica to yield feldspars, which also are alkali–alkaline-earth aluminosilicates. Feldspathoids commonly occur with feldspars.

Is Clinopyroxene a Pleochroic?

Clinopyroxene – XYZ2O. Optical properties: Colour and Pleochroism: Usually colourless, gray, pale green or pale brown, darker colours associated with Fe-rich varieties titanaugite is more distinctly coloured from brown/pink to violet. Cleavage: Parallel to {110}, which intersect at 90°.