Definition

A type of rock that is made mostly of very small particles called silt, which have been pressed together and hardened over time.

Example

The geologist collected samples of siltstone to study its formation.

Conversation

I found this interesting rock at the beach yesterday.

Oh really? What kind of rock was it?

It’s called siltstone and it's formed from compacted silt.

That sounds cool! I didn’t know rocks could be made that way.

Synonyms & Antonyms

Root Explanation

Siltstone is formed from "silt" (from Old English "silt", meaning fine sand or sediment) and "stone" (from Old English "stan", meaning rock or stone). The word refers to a type of rock that is composed primarily of silt-sized particles.

Memory Tip

Think of 'silt' as fine sediment and 'stone' as rock — together, they describe a rock made of fine particles.

Visually Confused Words