II. Class of Minerals
SULFIDES
Sulfides are natural compounds of sulfur with metals (iron, copper, zinc, lead, silver, gold, cobalt, nickel) or metalloids (arsenic, antimony, and bismuth). They most commonly form by crystallization from hot aqueous solutions from the Earth's crust, but they can also form sedimentarily under reducing conditions.
Among sulfides, there are many ore minerals. According to the old mining classification, they were divided into groups like ores, glitters, shiny minerals, and bluish minerals—groups of minerals with similar properties, especially luster. The latter group was recently distinguished as a separate mineral class. The sulfide class also includes tellurides, compounds of the mentioned metals or metalloids with tellurium.
Among sulfides, there are many ore minerals. According to the old mining classification, they were divided into groups like ores, glitters, shiny minerals, and bluish minerals—groups of minerals with similar properties, especially luster. The latter group was recently distinguished as a separate mineral class. The sulfide class also includes tellurides, compounds of the mentioned metals or metalloids with tellurium.
