Pronunciation: [ɡlˈɔːkəfˌe͡ɪn] (IPA) 
Glaucophane is a mineral that belongs to the amphibole group. Its name is derived from the Greek words "glaukos" which means "blue-green" and "phanos" which means "appearance". The word is pronounced as /ɡlɔːkəˌfeɪn/ with an emphasis on the second syllable. The "gl" sound is pronounced as in "glow" while the "au" sound is pronounced as in "how". The "ph" sound is pronounced as "f" and the "e" at the end of the word is silent.
Glaucophane is a mineral that belongs to the amphibole group, consisting of double-chain silicate minerals. It is typically found in metamorphic rocks, especially in blueschist facies, which are formed under high-pressure and low-temperature conditions. The name "glaucophane" is derived from the Greek words 'glaukos', meaning "bluish-green," and 'phaino,' meaning "to appear," referencing its characteristic bluish-green color.
Glaucophane has a monoclinic crystal system and can be found in prismatic or fibrous crystal forms. It has a distinctive, intense bluish-green color, often with a vitreous to pearly luster. The mineral possesses a relatively high hardness on the Mohs scale, ranging from 5.5 to 6. Its cleavage is perfect, meaning it can easily split into thin, flexible sheets.
Glaucophane is primarily composed of sodium, magnesium, aluminum, silicon, and oxygen, with the chemical formula (Na2, Mg, Fe)3(Al2Si8O22)(OH)2. It may also contain small amounts of other elements, including iron and calcium.
While not commonly used in industrial applications, glaucophane is valued as a collector's mineral due to its striking color and rarity. It is occasionally used as a gemstone in jewelry, particularly when properly cut to enhance its color and luster. Because of its association with specific geological conditions, the presence of glaucophane in a rock can provide insights into its formation and history.
The word "Glaucophane" has its etymology rooted in Greek. It is derived from the Greek words "glaucos", meaning "gleaming" or "shining", and "phanēs", meaning "appearing". Glaucophane is the name of a mineral that belongs to the amphibole group, typically occurring in blue or bluish-green colors. The term was coined in the early 19th century, combining the Greek descriptors to describe the mineral's appearance.
