Yellow streak

Yellow streak

Native sulphur is a bright yellow colour. It also has a yellow streak. Sulphur can also produce a nasty smell when it is damp - you would know it as rotten egg gas. It is sulphur's strong yellow colour, yellow streak, and smell that helps you to identify it.

Other minerals also have a yellow streak. Goethite is an iron ore that ranges from yellow to black in colour, but its streak is always browny yellow. Powdered orpiment was once used as a yellow pigment in paint. The radioactive minerals autunite and uranocircite both have yellow streaks.