Feldspathoids – Geology is the Way

Feldspathoids or foids are a family of rock-forming alkali-bearing aluminosilicates that form only in silica-undersaturated igneous rocks. The name derives from their chemical (and sometimes structural) similarity …

Feldspars

Last updated: 04.09.2021 07:36. Feldspars are alumosilicates of alcalic metals and form a significant portion of many volcanic and metamorphic rocks. As such, …

feldspathoid summary | Britannica

feldspathoid, Any of a group of alkali aluminosilicate minerals similar to the feldspars in composition but having a lower silica-alkali ratio or containing chloride, sulfide, sulfate, …

Feldspar

Feldspar is the name given to a group of minerals distinguished by the presence of alumina and silica (SiO 2) in their chemistry. This group includes aluminum silicates of soda, potassium, or lime. It is the single …

Do you know your ceramics? Part 2: feldspathic ceramics

Key points. Highlights the benefits of using feldspathic porcelain because of its optical properties. Discusses the limitations of feldspathic porcelain based on …

Plagioclase Feldspar: A group of common rock …

Plagioclase feldspars are important components of many building stones. Labradorite, spectrolite, sunstone, and moonstone are gem-quality plagioclase feldspars that are popular because of their optical phenomena.

Feldspathoid | Mineral Composition, Uses

Feldspathoid, any of a group of alkali aluminosilicate minerals similar to the feldspars in chemical composition but either having a lower silica-alkali ratio or containing chloride, sulfide, sulfate, or carbonate. They are …

Feldspar minerals make up over 50% of Earth's crust.

6.4.4: Feldspathoids

Analcime, a zeolite, is often considered to belong to the feldspathoid family. Other important feldspathoids include leucite, nepheline, sodalite, and lazurite. Leucite is a rare mineral found in K-rich …