analcite

Analcite is a tectosilicate mineral of the zeolite group. Its chemical formula is NaAlSi2O6·H2O. It is characterized by its cubic crystal system and often occurs as trapezohedral crystals. Analcite is typically white or colorless, though impurities can lead to grey or reddish hues. It has a vitreous luster and a hardness of around 5 to 5.5 on the Mohs scale. The specific gravity of analcite is between 2.07 and 2.27.

This mineral is a relatively common constituent of many igneous rocks, particularly those that are undersaturated in silica, such as nepheline syenites and alkali basalts. It can also form through hydrothermal alteration of other feldspathoids and volcanic glasses. Analcite is found in various geological settings worldwide, including oceanic islands, continental rift zones, and alkaline intrusions.

Analcite has limited economic significance, but it is of scientific interest to mineralogists and geologists due to its presence in specific rock types and its role in understanding petrogenesis. It has also been explored for potential applications in areas like ion exchange and catalysis, though zeolites with more open frameworks are generally preferred for these uses.