* Black Color: Basalt is often dark grey to black.
* Small Crystals: Basalt is a fine-grained igneous rock, meaning it cools quickly and doesn't have time to form large crystals.
* Volcanic Origin: Basalt forms from the cooling of lava flows.
However, other dark, fine-grained volcanic rocks exist. To be sure, you'd need more information, such as:
* Location: Where was the rock found?
* Texture: Is the rock glassy, bubbly, or porous?
* Hardness: Can you scratch the rock with a fingernail or a penny?
If you can provide more details, I can give you a more specific answer.
