👉 Brontolite is a type of mineral that is a part of the group called micas. It has a characteristic shiny, glassy appearance due to its silica content. Brontolites are often found in rocks and can vary in size from small grains to large crystals. The term "brontolite" refers to the crystal structure of brontolite. It is composed of a hexagonal lattice with a regular arrangement of the elements silicon, oxygen, and boron. The