fluorohapolla

Fluorohapolla is a rare and complex mineral belonging to the sorosilicate group, characterized by its unique chemical composition and crystal structure. The mineral was first identified in 1979 at the Poudrette Quarry in Quebec, Canada, and named for its fluorine content and its structural similarity to the more common mineral haplogranite. Fluorohapolla has the chemical formula Ca₄(Al,Mg)₃(Al,Mg)(SiO₄)₂(Si₂O₇)(OH,F)₂, indicating it contains calcium, aluminum, magnesium, silicon, oxygen, hydrogen, and fluorine.

Fluorohapolla typically forms as small, prismatic crystals that are often colorless or white, though specimens may exhibit faint yellow, green, or pink hues due to trace impurities. The mineral crystallizes in the monoclinic system and exhibits a vitreous to pearly luster. It is relatively soft, with a Mohs hardness of approximately 5 to 5.5, and has a specific gravity ranging from 2.9 to 3.0. Fluorohapolla is found in pegmatitic environments, often associated with other aluminum-rich silicates such as beryl, tourmaline, and topaz.

Due to its rarity, fluorohapolla is not commonly encountered in mineral collections. Specimens are primarily sourced from pegmatite deposits, particularly those with high fluorine content. The mineral’s occurrence is limited to a few well-known localities, including the type locality in Quebec, as well as pegmatites in Brazil and Madagascar. Its distinctive crystal habits and composition make it of interest to mineralogists studying complex silicate structures and the behavior of fluorine in geological formations.