The mineral howlite is a calcium boron silicate hydroxide, with the chemical formula Ca2B5SiO9 (OH) 5. Howlite crystals are white and usually black-veined. They have a monoclinic structure. Howlite usually occurs in nodular units (massive minerals with a veined surface). The mineral is neither magnetic nor radioactive. Howlite is named after the Canadian chemist, geologist and mineralogist Henry How, who discovered the mineral in Brookvill, Nova Scotia, Canada in 1868. Howlite is often used to decorate jewelry. Because of the porous structure, it is often colored to imitate other minerals. This is mainly done to mimic the much more precious turquoise. It is then referred to by the name turquenite.