Examine the texture of the sedimentary rock using a magnifying glass. Describe the texture of the sedimentary rock with particles that can be easily seen with the naked eye as "coarse," meaning it is composed of large pebbles (up to 2 mm) and sand. Describe a rock as "medium" texture if it contains small pebbles larger than 1/16 mm. Describe the sedimentary rock as "fine" if the particles consist almost entirely of tiny sand grains.
Use the magnifying glass to closely examine the shape of the pebbles and particles that form the sedimentary rock. Describe the particles as "rounded" (meaning they have no clearly defined edges) or "angular" (meaning the particles have defined corners). Categorize rounded particles as having been exposed to flowing water longer than rocks with angular particles.
Observe how the particles in the rock are sorted. Describe the sedimentary rock as poorly sorted if it contains a variety of different sized grains. Define a rock as well-sorted if the grains are similar in size. Break the rock with a hammer to examine layers within the rock.