humite

Humite is a mineral belonging to the humite group, which comprises a series of nesosilicates with the general formula Mg(Mg,Fe)n(SiO4)n+1(F,OH)2 where n ranges from 1 to 5. The specific formula for humite is Mg3(SiO4)2(F,OH)2, where n=2. Humite typically occurs as stubby prismatic crystals or as granular masses. Its color can vary widely, ranging from colorless to yellow, brown, or reddish-brown. The mineral is translucent to transparent and possesses a vitreous luster. It has a Mohs hardness of 6 to 6.5 and a specific gravity of approximately 3.1 to 3.3.

Humite is found in metamorphosed carbonate rocks, particularly those that have undergone contact metamorphism. It is also found in skarns and some igneous rocks. Common associated minerals include forsterite, clinohumite, chondrodite, spinel, and calcite. Humite is relatively rare, but it has been found in several locations worldwide, including Italy, Russia, the United States, and Canada. While not a commercially significant mineral, it is of interest to mineral collectors and geologists for its unusual chemical composition and occurrence in specific geological settings. The name "humite" honors Abraham Hume, 3rd Earl of Egmont, a mineral collector.