Nepheline

Nepheline is believed to provide a gentle energy that can help children or adults suffering from nightmares, improve one's love life, and bring a sense of harmony to the home. Many believe it has the power to eliminate emotional pain and relieve mental anguish. Keep it in the bedroom to improve intimate relationships. Carry it with you to open the flow of earth's energy and allow the full enjoyment of every day life.

Few faceted nepheline gems have been cut due to the rarity of gem-quality material. Faceted gems tend to be colorless, and no gem over two carats is known. The variety Elaeolite shows a cat's eye effect and is cut into cabochons. Colorful red and green cabochons are more valuable than brown or gray. Quartz and nepheline can appear similar, but Quartz has a higher hardness, which can be ascertained by a scratch test in an inconspicuous place.

Nepheline is used to lower the melting temperature when making ceramics and glass, which also gives it resistance to getting scratched or broken. Nepheline is also used in rock wool insulation, roofing granules, building stone, and in bathrooms to make toilet bowls or sinks.

The aluminosilicate backbone of nepheline has a fairly open structure of interlocked six-member rings. This resembles the structure of tridymite, with aluminum substituting for every other silicon atom. This structure produces one nearly hexagonal interstitial site and three irregular interstitial sites per unit cell. In ideal nepheline, the hexagonal sites are occupied by potassium ions and the irregular sites by smaller sodium ions, yielding an atomic ratio of sodium to potassium of (3:1). This corresponds to an ideal weight percentage of K2O of 8.1% The range of compositions seen in natural nepheline is 3% to 12% K2O. Small amounts of calcium may be present as well. At elevated temperature, nepheline forms a complete solid solution series with kalsilite, KAlSiO4. At temperatures below about 1,000 °C (1,830 °F), there is a wide miscibility gap between nepheline and kalsilite, similar to the miscibility gap between microcline and albite. A composition falling in this gap will experience exsolution as it cools, where nepheline and kalsilite separate into separate microscopic layers (lamellae).

Nephelinite is a rock-forming mineral found in silica-poor igneous rocks. These include nepheline syenite, foidite, and phonolite. It is often found along with leucite, sodalite, potassium feldspars, and sodium-rich plagioclase, amphiboles, or pyroxenes, but almost never in association with quartz. Notable outcrops of nepheline-bearing rocks are found on the Kola Peninsula; in Norway and South Africa; and at Litchfield, Maine; Magnet Cove, Arkansas; and Beemerville, New Jersey, in the United States. Syenites found near Bancroft, Ontario contain large deposits of high-purity nepheline. Elaeolite (a name given by M. H. Klaproth 1809, from Greek words for oil [ἔλαίον] and stone [λίθος]; German: Fettstein) is a massive form of translucent nepheline with a darker color and greasy luster.