Lab 1 Roundness and Sphericity

In this lab you will determine the roundness and sphericity of a number of sedimentary particles and will investigate the relationship between these two properties of particles.

RoundnessRoundness refers to the sharpness of the corners and edges of a grain.

Angular

Sub-rounded

Well-rounded

To determine the roundness of our grains we will estimate by a visual comparison to grains of known roundness.

SphericitySphericity measures the degree to which a particle approaches a spherical shape. It will be determined for our grains by measuring the three linear dimensions (longest(L), Intermediate (I) & Shortest (S) diameters).

Sphericity Measurements

Review . . .

Measurement = 1.28

How do you use the calipers?