Massachusetts Soil Evaluator Practice Test

The main idea is how soil particle sizes are categorized. Sand is divided into ranges, and the fine sand category is defined as roughly 0.25 to 0.1 mm. A particle about 0.15 mm sits squarely in that interval, so it is classified as fine sand.

Other categories here are much larger or much smaller than 0.15 mm: very coarse sand is 2 to 1 mm and would be visibly chunkier, while silt and clay are defined as much smaller than 0.25 mm—silt from about 0.05 to 0.002 mm and clay less than 0.002 mm. Since 0.15 mm is larger than silt and clay sizes, it isn’t those categories.