Don't be put off by the aged front cover of this booklet; it was written by experts and contains a good number of ideas for practical work on rocks. Although it was written with keystage four students in mind and for a now defunct version of the national curriculum the experiments are easily accessible by keystage three students.
Topic R2, on page 36 and 37 (note the two page spread) gives details of how students can explore the conditions under which sedimentary rocks formed. Teachers may prefer to demonstrate the first two activities to ensure that students notice the ripple marks left in the sand. The third activity, producing a graded bed, could be set up by students at the beginning of the lesson; coming back after the teacher demonstrations when it had settled.
Activity R5, on pages 16 and 17 suggests ideas for investigating igneous rock formation. Again the first activity works very well as a teacher led demonstration in a large beaker. To get a good layer of wax at the bottom melt it and then cover with sand when it has solidified again. Make sure your candle wax is red so that it looks like magma and keep the Bunsen burner still, this is one time you do want hot spots. You should get a lovely plume of "magma" that bursts through the sand and then solidifies when it hits the cold water - a lovley analogue of a vent pipe in a volcano.
It is unlikely that teachers will want to use the worksheets as they stand in the booklet but the experimental details given can easily be explained by teachers or turned into a new worksheet. Teachers will appreciate the detailed background information given and the suggestions provided for further development.