Known since ancient times as copperas and as green vitriol , the blue-green heptahydrate is the most common form of this material.
Kaynak: Iron(II) sulfate

It is sometimes known as yellow copperas. Other occurrences are in California, Nevada, and in the filled paleo sinkholes and caves of
Kaynak: Copiapite

regaining its blue color, and is known as blue copperas Copper(II) sulfate pentahydrate can easily be produced by crystallization from
Kaynak: Copper(II) sulfate