Preview of Lab 4. Classification of sediments Reading a ternary diagramFinding Clay : Silt RatioFinding Mud : Sand Ratio. Objectives of Lab 5. Principle axes of sedimentary particlesGrain shapeRoundness SphericityForm. Principle Axes of Sedimentary Particles . Each sedimentary particle has three main axes: L (a): Long axis I (b): Intermediate axis S (c): Short axis .