Here's a breakdown:

* Mohs Hardness Scale: This scale measures a mineral's resistance to scratching. It ranges from 1 (softest) to 10 (hardest).

* 5 to 6: This means basalt can be scratched by steel (hardness 5.5) but not by glass (hardness 5.5 to 6.5). It's harder than common materials like copper (hardness 3) and iron (hardness 4).

Important Note: While basalt's hardness is generally considered "hard," it can vary slightly depending on factors like:

* Composition: Different types of basalt contain varying amounts of minerals, which can affect their hardness.

* Porosity: Basalt with more pores can be slightly less hard.

Overall, basalt is a durable and strong rock commonly used in construction and other applications where hardness is a desirable property.