A standalone art lesson that is suitable for KS3. This resource can be used to either explore basic key skills (tonal shading). Or is ideal for a cover lesson. Students are encouraged to explore tonal range when shading to create a colourful gemstone. The focus for the lesson is aimed at developing students’ ability to create tonal range, and to apply neat smooth shading whilst creating a gradient with each colour they use. The resource can be adapted so that students can use either a pencil, or coloured pencils of a certain colour to shade the gemstone. The worksheet contains a ‘starter activity’ whereby students create a tonal bar in their chosen colour, which is ideal for settling students at the start of the lesson. The worksheet also offers success criteria, and explanations of key words in order to guide students independent practice.