Assertion: copper sulfate | /r/ObjectUse | used as dye
Facets:
value: in paints
type: LOCATION
value: in past
type: TEMPORAL
value: in some vitrals
type: LOCATION
Source sentences:
text: Copper sulfate has been used as a dye in some vitrals and paints in past, and today its use as coloring ingredients in paints still remains.