For alexandrite to form, some chromium would also have had to be present.
en.wikipedia.org However, during tempering, elements like chromium, vanadium, and molybdenum precipitate with the carbon.
en.wikipedia.org Another is chromium polynicotinate, and six forms of chromium are sold for this purpose.
en.wikipedia.org The state is rich in mineral resources such as coal, limestone, iron, nickel, cobalt, chromium, and marble.
en.wikipedia.org The region also contains many natural resources such as petroleum, iron ore, copper, chromium ore, zinc, tungsten, mica, silver, gold, diamonds, hardwoods, limestone and hydropower.
en.wikipedia.org