Silt is granular material of a size between sand and clay, whose mineral origin is quartz[1] and feldspar. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water (also known as a suspended load) and soil in a body of water such as a river. It may also exist as soil deposited at the bottom of a water body, like mudflows from landslides. Silt has a moderate specific area with a typically non-sticky, plastic feel.
Compare the raccoon droppings to that of a medium-sized dog. Raccoon poop looks much like dog feces: dark, tubular in shape, up to 1/2 inch or so in diameter and usually in well-formed, blunt segments. They many have a strong odor. Older feces can resemble dry leaves or a small pile of debris.
Squirrel and rat droppings are similar at quick glance. Color can be useful in helping you figure out which rodents are in your presence. For the most part, squirrel feces is paler than that of rats -- likely because their food intake is nowhere near as diverse as the latter.