Refraktorite

Refraktorite is a rare mineral that was first discovered in 1979 in the Kola Peninsula, Russia. It is named for its unique property of refracting light, which is a characteristic of its crystal structure. Refraktorite is typically found in association with other rare minerals in granitic pegmatites, which are igneous rocks formed from the slow crystallization of magma.

The mineral has a chemical composition of (Na,K)2Ca2(Si,Al)8O20·H2O, indicating it is a silicate mineral with sodium, potassium, and calcium as its primary cations. Its crystal system is monoclinic, and it often forms prismatic crystals with a distinct cleavage. Refraktorite is usually colorless or white, but it can also exhibit shades of gray, yellow, or brown due to impurities.

Refraktorite's optical properties are particularly noteworthy. It exhibits strong pleochroism, meaning it displays different colors when viewed from different angles. This property is due to its complex crystal structure, which allows for the selective absorption of light. Additionally, refraktorite has a high refractive index, which contributes to its ability to refract light.

Despite its rarity and unique properties, refraktorite is not considered a valuable gemstone. Its primary interest lies in the field of mineralogy, where it serves as an example of a complex silicate mineral with interesting optical properties. The study of refraktorite and similar minerals contributes to our understanding of the geological processes that form granitic pegmatites and the diverse range of minerals that can be found within them.