Mineral, Zn2SiO4; sp. gr. 4.0; hardness 5.5; trigonal; greenish-yellow, but can vary to brown or white; vitreous lustre; crystals can be prismatic, but it usually forms granular or massive aggregates; strongly fluorescent; occurs mainly in the oxidized zones of zinc deposits. It is named after King William I of the Netherlands.
Subjects: Earth Sciences and Geography.