Definition

A type of rock that is made from very small particles of mud and clay, and is similar to shale but does not have layers.

Example

The geologist collected samples of mudstone to study its properties.

Conversation

Have you ever heard of mudstone?

Yeah, isn't it that dark rock formed from mud?

Exactly! It's interesting how it differs from shale.

Right, and I love how it's used in construction sometimes.

Synonyms & Antonyms

Root Explanation

Mudstone is formed from "mud" (from Old English "mudd", meaning wet earth or soft soil) and "stone" (from Old English "stan", meaning rock or stone). The word refers to a type of rock that is composed primarily of mud or clay particles that have hardened over time.

Memory Tip

Think of 'mud' as wet earth and 'stone' as rock — mudstone is a rock made from hardened mud.

Visually Confused Words