What is another word for siltstone?
Pronunciation: [sˈɪltstə͡ʊn] (IPA) 
Siltstone is a common sedimentary rock composed of fine-grained, compacted sediment particles that are smaller than sand-sized particles but larger than clay-sized particles. There are several synonyms for siltstone based on their color, composition, and origin. Some of the common synonyms for siltstone include argillite, mudstone, shale, and greywacke. Argillite is a fine-grained sedimentary rock that is often formed from clay minerals. Mudstone is a type of fine-grained sedimentary rock with a silt content higher than clay content. Shale is a fine-grained sedimentary rock formed from mud and clay-sized sediment particles. Greywacke is a type of sandstone that contains a significant amount of silt or mud-sized grains.
