Leucite (from the Greek word leukos meaning white) is a rock-forming mineral of the feldspathoid group, silica-undersaturated and composed of potassium and aluminium tectosilicate KAlSi 2 O 6. [4] Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are ...

Apr 23, 2023 · Leucite is a rather rare mineral, occurring only in igneous rocks, usually in the recent lavas; rarely observed in deepseated rocks. Found in rocks in which the amount of silica in the magma was insufficient to combine with the potassium to form feldspar.

From the Greek "leucos," for white, in allusion to its common colour. Leucite is common in some volcanic rocks in which it crystallises with a cubic crystal structure at high temperature (ca. 900°C).

Leucite is a member of the feldspathoid group, forming directly from cooling lava in volcanic rock. It forms in low-silica environments where little Quartz is present. When Leucite forms at high temperatures, it crystallizes as isometric crystals in trapezohedral crystal form.

Leucite, one of the most important feldspathoid minerals, a potassium aluminosilicate (KAlSi2O6). It occurs only in igneous rocks, particularly potassium-rich, silica-poor, recent lavas. Some important localities include Rome; Uganda; and Leucite Hills, …

Leucite. Comments: Large single crystal of dark gray leucite. Location: Roccamonfina, Caserta Province, Campania, Italy. Scale: 20x20x20 mm. © John Betts - Fine Minerals

Apr 12, 2022 · You're more likely to find faceted leucites in mineral collections than jewelry collections. Although some stones may have unusual color flashes, their general appearance doesn't typically lend itself to jewelry wear.

The leucite structure is characterized by two distinct sites, available for large cations; the larger sites contain K + ions and the smaller sites are vacant, yielding a very open, low-density structure. Leucite is common in some volcanic rocks in which it crystallises with a cubic crystal structure at high temperature (ca. 900°C), forming ...

Leucitite or leucite rock is an igneous rock containing leucite. It is scarce, many countries such as England being entirely without them. However, they are of wide distribution, occurring in every quarter of the globe.

May 8, 2023 · Leucite is a white to gray stone that’s rare as a gem but important in dentistry. It has unusual, intriguing optical properties. Learn all about leucite prices, properties, history, and more!