hexagonite

Hexagonite is a rare and unusual mineral that was first discovered in 1967 in the Kola Peninsula of Russia. It is named for its distinctive hexagonal crystal structure, which is a result of its unique chemical composition. Hexagonite is a complex oxide mineral, with the chemical formula (Mg,Fe)2Al(AlSiO5)(OH)4. It is typically found in metamorphic rocks, particularly in association with other aluminum-rich minerals such as sillimanite and andalusite.

Hexagonite crystals are usually small, ranging from a few millimeters to a centimeter in size. They are often found in aggregates or clusters, and their hexagonal shape is a result of the mineral's crystal lattice structure. The mineral is typically a deep blue or blue-green color, although it can also be found in shades of green, brown, or even colorless. Its hardness on the Mohs scale is around 6.5 to 7, making it relatively hard and durable.

Hexagonite is not commonly used in industry or jewelry due to its rarity and the difficulty in finding large, well-formed crystals. However, it is of interest to mineral collectors and geologists due to its unique crystal structure and the geological conditions under which it forms. The mineral's rarity and the specific conditions required for its formation make it a subject of ongoing study in the fields of mineralogy and geology.