The main difference between a colloid and a suspension is that a suspension will separate into particles, but a colloid will not. A colloid is the middle line between a suspension and a solution.
A suspension is composed of at least two substances that are visible in the suspension. These substances are heterogeneous in nature and they are able to be separated. A suspension is also larger than 10,000 Angstroms. When comparing a suspension, a colloid and a solution, the suspension will most likely be affected by the sedimentation of particles. The light that is seen in a suspension is variable. Both a suspension and a colloid are cloudy.
A colloid often looks similar to a suspension because they are both cloudy in nature, but a colloid is homogenous, unlike a suspension. The particles are not easily distinguishable and they are not easily separated. A colloid can vary in size between 10 and 1,000 Angstroms, but is always smaller than a suspension. The particles that are in the colloid are able to be distinguished by light through the Tyndall light effect. Colloid mixtures are not able to be distinguished by any amount of sedimentation and are not affected by sedimentation.