Meionite is a mineral that belongs to the group of sorosilicates, specifically the garnet group. It is named after the Greek word "meiōn," which means smaller or less. Meionite is commonly classified as a calcium aluminum garnet, with the chemical formula Ca2Al2SiO7. It is characterized by its high calcium content, which differentiates it from other garnets within the group.
The mineral typically forms in metamorphic rocks, particularly those that have undergone high-pressure conditions. Meionite is predominantly found in regions where calc-silicate rocks and skarns occur, as well as in high-grade metamorphic terranes. Many localities around the world have yielded meionite, including Norway, the Alps, Russia, and the United States.
Meionite is generally recognized by its distinctive crystal structure and physical properties. It typically occurs as dodecahedral or trapezohedral crystals, but can also be found as massive granular aggregates. The color of meionite ranges from pale yellow to gray or brownish-gray. It has a vitreous luster and a transparent to translucent appearance. Meionite has an average hardness of 6.5 to 7 on the Mohs scale, which makes it relatively durable.
Due to its intriguing crystal structure and unique properties, meionite has both industrial and ornamental uses. In industry, it is sometimes employed as a refractory material, capable of withstanding high temperatures. As an ornamental stone, meionite is occasionally used in jewelry, typically as a gemstone for collectors and mineral enthusiasts.
