Silt is soil or rock that developed from granular material of a specific grain size.
Silty soil has much smaller particles than sandy soil, so it is smooth to the touch. When moistened, it is soapy slick. When rolled between the fingers, dirt is left on the skin.
Silty soil retains water longer, but it can’t hold on to as many nutrients as you’d want it to, though it’s fairly fertile. Due to its moisture-retentive quality, silty soil is cold and drains poorly.