Based on origin:
* Volcanic rock: This is the most general term, encompassing all rocks formed from volcanic activity.
* Extrusive igneous rock: This is a more specific term, highlighting the fact that lava rock formed from magma that erupted onto the Earth's surface.
Based on appearance:
* Basalt: This is a specific type of volcanic rock that is often dark-colored and fine-grained, and commonly used for landscaping.
* Scoria: This is a type of volcanic rock with a bubbly texture, often used for landscaping and construction.
* Cinder: This is a type of volcanic rock that is smaller and lighter than scoria, often used for landscaping and as a soil amendment.
Based on usage:
* Landscaping rock: This is a broad term that covers any type of rock used for landscaping purposes.
* Garden rock: This is a more specific term for lava rock used in gardens.
Ultimately, the best word to use depends on the context and what you want to convey.
